diff --git a/package.json b/package.json
index 3f546371324bec..712873253bf433 100644
--- a/package.json
+++ b/package.json
@@ -67,6 +67,7 @@
     "chokidar": "^3.3.1",
     "cssnano": "^4.1.10",
     "debug": "^4.1.1",
+    "dotenv": "^8.2.0",
     "es-module-lexer": "^0.3.18",
     "esbuild": "^0.3.2",
     "etag": "^1.8.1",
diff --git a/playground/.env b/playground/.env
new file mode 100644
index 00000000000000..ae9a143be28507
--- /dev/null
+++ b/playground/.env
@@ -0,0 +1 @@
+CUSTOMIZE_ENV_VARIABLE=9527
\ No newline at end of file
diff --git a/playground/App.vue b/playground/App.vue
index 0495478772f611..34e7f4048cc80a 100644
--- a/playground/App.vue
+++ b/playground/App.vue
@@ -6,9 +6,7 @@
   <p class="base">
     <code>__BASE__: {{ base }}</code>
   </p>
-  <p class="node_env">
-    <code>process.env.NODE_ENV: {{ env }}</code>
-  </p>
+  <TestEnv />
   <h2>Async Component</h2>
   <TestAsync />
   <TestModuleResolve />
@@ -28,6 +26,7 @@
 
 <script>
 import { defineAsyncComponent } from 'vue'
+import TestEnv from './TestEnv.vue'
 import TestModuleResolve from './TestModuleResolve.vue'
 import TestHmr from './TestHmr.vue'
 import TestPostCss from './TestPostCss.vue'
@@ -45,10 +44,10 @@ import TestTransform from './TestTransform.vue'
 export default {
   data: () => ({
     dev: __DEV__,
-    base: __BASE__,
-    env: process.env.NODE_ENV
+    base: __BASE__
   }),
   components: {
+    TestEnv,
     TestModuleResolve,
     TestHmr,
     TestPostCss,
diff --git a/playground/TestEnv.vue b/playground/TestEnv.vue
new file mode 100644
index 00000000000000..386129c65e7f55
--- /dev/null
+++ b/playground/TestEnv.vue
@@ -0,0 +1,24 @@
+<template>
+  <h2>Environment Variables</h2>
+  <p class="node-env">
+    <code>process.env.NODE_ENV: {{ NODE_ENV }}</code>
+  </p>
+  <p class="customize-env-variable">
+    <code>process.env.CUSTOMIZE_ENV_VARIABLE: {{ CUSTOMIZE_ENV_VARIABLE }}</code>
+  </p>
+  <p class="defined-variable-names">
+    <code>Defined environment variable names: {{ variableNames }}</code>
+  </p>
+</template>
+
+<script>
+export default {
+  data() {
+    return {
+      NODE_ENV: process.env['NODE_ENV'],
+      CUSTOMIZE_ENV_VARIABLE: process.env.CUSTOMIZE_ENV_VARIABLE,
+      variableNames: Object.keys(process.env).join(",")
+    }
+  }
+}
+</script>
diff --git a/src/node/build/index.ts b/src/node/build/index.ts
index 76cf47a98c6fbb..dad327677f5565 100644
--- a/src/node/build/index.ts
+++ b/src/node/build/index.ts
@@ -159,7 +159,8 @@ export async function build(options: BuildConfig = {}): Promise<BuildResult> {
     minify = true,
     silent = false,
     sourcemap = false,
-    shouldPreload = null
+    shouldPreload = null,
+    env = {}
   } = options
 
   let spinner: Ora | undefined
@@ -213,8 +214,10 @@ export async function build(options: BuildConfig = {}): Promise<BuildResult> {
       // Vue templates are compiled into js and included in chunks.
       createReplacePlugin(
         {
-          'process.env.NODE_ENV': '"production"',
-          'process.env.': `({}).`,
+          'process.env': `(${JSON.stringify({
+            ...env,
+            NODE_ENV: 'production'
+          })})`,
           __DEV__: 'false',
           __BASE__: JSON.stringify(publicBasePath)
         },
diff --git a/src/node/config.ts b/src/node/config.ts
index 96dc8f89bde747..84422675255351 100644
--- a/src/node/config.ts
+++ b/src/node/config.ts
@@ -1,9 +1,7 @@
 import path from 'path'
 import fs from 'fs-extra'
 import chalk from 'chalk'
-import { createEsbuildPlugin } from './build/buildPluginEsbuild'
-import { ServerPlugin } from './server'
-import { Resolver } from './resolver'
+import { DotenvParseOutput } from 'dotenv'
 import { Options as RollupPluginVueOptions } from 'rollup-plugin-vue'
 import { CompilerOptions } from '@vue/compiler-sfc'
 import Rollup, {
@@ -11,6 +9,9 @@ import Rollup, {
   OutputOptions as RollupOutputOptions,
   OutputChunk
 } from 'rollup'
+import { createEsbuildPlugin } from './build/buildPluginEsbuild'
+import { ServerPlugin } from './server'
+import { Resolver } from './resolver'
 import { Transform } from './transform'
 import { DepOptimizationOptions } from './depOptimizer'
 import { IKoaProxiesOptions } from 'koa-proxies'
@@ -82,6 +83,10 @@ export interface SharedConfig {
         factory?: string
         fragment?: string
       }
+  /**
+   * Environment variables .
+   */
+  env?: DotenvParseOutput
 }
 
 export interface ServerConfig extends SharedConfig {
@@ -253,17 +258,18 @@ export async function resolveConfig(
   configPath: string | undefined
 ): Promise<ResolvedConfig | undefined> {
   const start = Date.now()
+  const cwd = process.cwd()
   let config: ResolvedConfig | undefined
   let resolvedPath: string | undefined
   let isTS = false
   if (configPath) {
-    resolvedPath = path.resolve(process.cwd(), configPath)
+    resolvedPath = path.resolve(cwd, configPath)
   } else {
-    const jsConfigPath = path.resolve(process.cwd(), 'vite.config.js')
+    const jsConfigPath = path.resolve(cwd, 'vite.config.js')
     if (fs.existsSync(jsConfigPath)) {
       resolvedPath = jsConfigPath
     } else {
-      const tsConfigPath = path.resolve(process.cwd(), 'vite.config.ts')
+      const tsConfigPath = path.resolve(cwd, 'vite.config.ts')
       if (fs.existsSync(tsConfigPath)) {
         isTS = true
         resolvedPath = tsConfigPath
@@ -326,6 +332,17 @@ export async function resolveConfig(
       }
     }
 
+    // load environment variables
+    const envConfigPath = path.resolve(cwd, '.env')
+    if (fs.existsSync(envConfigPath) && fs.statSync(envConfigPath).isFile()) {
+      const env = require('dotenv').config()
+      if (env.error) {
+        throw env.error
+      }
+
+      config.env = env.parsed
+    }
+
     require('debug')('vite:config')(
       `config resolved in ${Date.now() - start}ms`
     )
diff --git a/src/node/server/serverPluginHtml.ts b/src/node/server/serverPluginHtml.ts
index c418fbbc042d6f..5d58dee5c356e6 100644
--- a/src/node/server/serverPluginHtml.ts
+++ b/src/node/server/serverPluginHtml.ts
@@ -20,16 +20,21 @@ export const htmlRewritePlugin: ServerPlugin = ({
   root,
   app,
   watcher,
-  resolver
+  resolver,
+  config
 }) => {
   // inject __DEV__ and process.env.NODE_ENV flags
   // since some ESM builds expect these to be replaced by the bundler
+  const { env = {} } = config
   const devInjectionCode =
     `\n<script type="module">\n` +
     `import "${hmrClientPublicPath}"\n` +
     `window.__DEV__ = true\n` +
     `window.__BASE__ = '/'\n` +
-    `window.process = { env: { NODE_ENV: 'development' }}\n` +
+    `window.process = { env: ${JSON.stringify({
+      ...env,
+      NODE_ENV: 'development'
+    })}}\n` +
     `</script>\n`
 
   const scriptRE = /(<script\b[^>]*>)([\s\S]*?)<\/script>/gm
diff --git a/test/test.js b/test/test.js
index a713d086852108..607224f39ad757 100644
--- a/test/test.js
+++ b/test/test.js
@@ -97,9 +97,15 @@ describe('vite', () => {
     test('env variables', async () => {
       expect(await getText('.dev')).toMatch(`__DEV__: ${!isBuild}`)
       expect(await getText('.base')).toMatch(`__BASE__: /`)
-      expect(await getText('.node_env')).toMatch(
+      expect(await getText('.node-env')).toMatch(
         `process.env.NODE_ENV: ${isBuild ? 'production' : 'development'}`
       )
+      expect(await getText('.customize-env-variable')).toMatch(
+        'process.env.CUSTOMIZE_ENV_VARIABLE: 9527'
+      )
+      expect(await getText('.defined-variable-names')).toMatch(
+        'Defined environment variable names: CUSTOMIZE_ENV_VARIABLE,NODE_ENV'
+      )
     })
 
     test('module resolving', async () => {
diff --git a/yarn.lock b/yarn.lock
index 07c527548954f5..ab0c48c2886756 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2432,6 +2432,11 @@ dot-prop@^5.2.0:
   dependencies:
     is-obj "^2.0.0"
 
+dotenv@^8.2.0:
+  version "8.2.0"
+  resolved "https://registry.yarnpkg.com/dotenv/-/dotenv-8.2.0.tgz#97e619259ada750eea3e4ea3e26bceea5424b16a"
+  integrity sha512-8sJ78ElpbDJBHNeBzUbUVLsqKdccaa/BXF1uPTw3GrvQTBgrQrtObr2mUrE38vzYd8cEv+m/JBfDLioYcfXoaw==
+
 duplexer@0.1.1:
   version "0.1.1"
   resolved "https://registry.yarnpkg.com/duplexer/-/duplexer-0.1.1.tgz#ace6ff808c1ce66b57d1ebf97977acb02334cfc1"