diff --git a/.gitignore b/.gitignore
index fd1b80cce6b..a076a1193fe 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,4 @@ mrgit.json
 
 build/
 !packages/ckeditor5-build-*/build
+.DS_Store
diff --git a/packages/ckeditor5-paste-from-office/src/filters/space.js b/packages/ckeditor5-paste-from-office/src/filters/space.js
index 34d1dee122d..7fdab4fecb2 100644
--- a/packages/ckeditor5-paste-from-office/src/filters/space.js
+++ b/packages/ckeditor5-paste-from-office/src/filters/space.js
@@ -39,9 +39,13 @@ export function normalizeSpacing( htmlString ) {
  */
 export function normalizeSpacerunSpans( htmlDocument ) {
 	htmlDocument.querySelectorAll( 'span[style*=spacerun]' ).forEach( el => {
-		const innerTextLength = el.innerText.length || 0;
+		// For paste contents from WPS Office, the span's inner text is not all of spaces or blank,
+		// so we should keep the origin contents, or replace ONLY space characters.
+		if ( el.innerText.trim().length === 0 ) {
+			const innerTextLength = el.innerText.length || 0;
 
-		el.innerHTML = Array( innerTextLength + 1 ).join( '\u00A0 ' ).substr( 0, innerTextLength );
+			el.innerHTML = Array( innerTextLength + 1 ).join( '\u00A0 ' ).substr( 0, innerTextLength );
+		}
 	} );
 }
 
diff --git a/packages/ckeditor5-paste-from-office/tests/filters/space.js b/packages/ckeditor5-paste-from-office/tests/filters/space.js
index 9424cccf337..1e57d87fa2c 100644
--- a/packages/ckeditor5-paste-from-office/tests/filters/space.js
+++ b/packages/ckeditor5-paste-from-office/tests/filters/space.js
@@ -136,6 +136,23 @@ describe( 'PasteFromOffice - filters', () => {
 
 				expect( htmlDocument.body.innerHTML.replace( /'/g, '"' ).replace( /: /g, ':' ) ).to.equal( expected );
 			} );
+
+			it( 'should not normalize spaces inside special "span.spacerun" elements pasted from WPS', () => {
+				const input = '<p class=MsoNormal ><span style="mso-spacerun:\'yes\';font-family:等线;' +
+					'mso-bidi-font-family:\'Times New Roman\';font-size:10.5000pt;mso-font-kerning:1.0000pt;" >' +
+					'<font face="等线" >感受非遗魅力，弘扬传统文化，</font></span></p>';
+
+				const expected = input;
+
+				const domParser = new DOMParser();
+				const htmlDocument = domParser.parseFromString( input, 'text/html' );
+
+				expect( htmlDocument.body.innerHTML.replace( /'/g, '"' ).replace( /: /g, ':' ) ).to.equal( expected );
+
+				normalizeSpacerunSpans( htmlDocument );
+
+				expect( htmlDocument.body.innerHTML.replace( /'/g, '"' ).replace( /: /g, ':' ) ).to.equal( expected );
+			} );
 		} );
 	} );
 } );