diff --git a/docs/api/en/materials/MeshStandardMaterial.html b/docs/api/en/materials/MeshStandardMaterial.html
index 1c33d7ce6cda7f18331a4553a5d97b23f4564317..35f8ea825cca8cbc111534469c8c0d24fde0b64f 100644
--- a/docs/api/en/materials/MeshStandardMaterial.html
+++ b/docs/api/en/materials/MeshStandardMaterial.html
@@ -201,7 +201,7 @@
 		<h3>[property:Float metalness]</h3>
 		<p>
 			How much the material is like a metal. Non-metallic materials such as wood or stone use 0.0, metallic use 1.0, with nothing
-			(usually) in between. Default is 0.5. A value between 0.0 and 1.0 could be used for a rusty metal look. If metalnessMap is
+			(usually) in between. Default is 0.0. A value between 0.0 and 1.0 could be used for a rusty metal look. If metalnessMap is
 			also provided, both values are multiplied.
 		</p>
 
@@ -245,7 +245,7 @@
 
 		<h3>[property:Float roughness]</h3>
 		<p>
-			How rough the material appears. 0.0 means a smooth mirror reflection, 1.0 means fully diffuse. Default is 0.5.
+			How rough the material appears. 0.0 means a smooth mirror reflection, 1.0 means fully diffuse. Default is 1.0.
 			If roughnessMap is also provided, both values are multiplied.
 		</p>
 
diff --git a/docs/api/zh/materials/MeshStandardMaterial.html b/docs/api/zh/materials/MeshStandardMaterial.html
index e8a41d1d736f89b8f27416c009409ecbd345e02a..ceb64e5394074a66c5d453bf86e43a9a8e8dd378 100644
--- a/docs/api/zh/materials/MeshStandardMaterial.html
+++ b/docs/api/zh/materials/MeshStandardMaterial.html
@@ -164,7 +164,7 @@
 
 		<h3>[property:Float metalness]</h3>
 		<p> 材质与金属的相似度。非金属材质，如木材或石材，使用0.0，金属使用1.0，通常没有中间值。
-			默认值为0.5。0.0到1.0之间的值可用于生锈金属的外观。如果还提供了metalnessMap，则两个值相乘。
+			默认值为0.0。0.0到1.0之间的值可用于生锈金属的外观。如果还提供了metalnessMap，则两个值相乘。
 		</p>
 
 		<h3>[property:Texture metalnessMap]</h3>
@@ -197,7 +197,7 @@
 		</p>
 
 		<h3>[property:Float roughness]</h3>
-		<p> 材质的粗糙程度。0.0表示平滑的镜面反射，1.0表示完全漫反射。默认值为0.5。如果还提供roughnessMap，则两个值相乘。
+		<p> 材质的粗糙程度。0.0表示平滑的镜面反射，1.0表示完全漫反射。默认值为1.0。如果还提供roughnessMap，则两个值相乘。
 		</p>
 
 		<h3>[property:Texture roughnessMap]</h3>
diff --git a/src/materials/MeshStandardMaterial.js b/src/materials/MeshStandardMaterial.js
index cbbe32dc34d1cfb4a2e6bcf102c708af2978e50e..c66511d3afd972c573532a44a80874ac4a9be845 100644
--- a/src/materials/MeshStandardMaterial.js
+++ b/src/materials/MeshStandardMaterial.js
@@ -64,8 +64,8 @@ function MeshStandardMaterial( parameters ) {
 	this.type = 'MeshStandardMaterial';
 
 	this.color = new Color( 0xffffff ); // diffuse
-	this.roughness = 0.5;
-	this.metalness = 0.5;
+	this.roughness = 1.0;
+	this.metalness = 0.0;
 
 	this.map = null;
 
diff --git a/test/unit/example/exporters/GLTFExporter.tests.js b/test/unit/example/exporters/GLTFExporter.tests.js
index f5aa8e7f750230a2c5a9a2754effce2f495c43ed..57614441f1d3ab1707209c8ce6808a8e3312abd8 100644
--- a/test/unit/example/exporters/GLTFExporter.tests.js
+++ b/test/unit/example/exporters/GLTFExporter.tests.js
@@ -81,8 +81,8 @@ export default QUnit.module( 'Exporters', () => {
 				assert.smartEqual( {
 
 					baseColorFactor: [ 1, 0, 0, 1 ],
-					metallicFactor: 0.5,
-					roughnessFactor: 0.5
+					metallicFactor: 0.0,
+					roughnessFactor: 1.0
 
 				}, material.pbrMetallicRoughness, 'material' );