diff --git a/properties/backgrounds/background-size.htm b/properties/backgrounds/background-size.htm
index 9e21e8ba..6da1d63d 100644
--- a/properties/backgrounds/background-size.htm
+++ b/properties/backgrounds/background-size.htm
@@ -203,4 +203,4 @@ <h2>length</h2>
 <script src="../../js/jquery.js"></script>
 <script src="../../js/inner.js"></script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/properties/dimension/height.htm b/properties/dimension/height.htm
index a16ee917..72d3cd19 100644
--- a/properties/dimension/height.htm
+++ b/properties/dimension/height.htm
@@ -69,7 +69,7 @@ <h2 class="tit">取值：</h2>
 				<dt><a href="../../values/length/length.htm">&lt;length&gt;</a>：</dt>
 				<dd>用长度值来定义高度。不允许负值</dd>
 				<dt><a href="../../values/numeric/percentage.htm">&lt;percentage&gt;</a>：</dt>
-				<dd>用百分比来定义高度。不允许负值</dd>
+				<dd>用百分比来定义高度。百分比参照包含块高度。不允许负值</dd>
 			</dl>
 		</div>
 	</section>
@@ -156,4 +156,4 @@ <h2 class="tit">示例：</h2>
 <script src="../../js/jquery.js"></script>
 <script src="../../js/inner.js"></script>
 </body>
-</html>
\ No newline at end of file
+</html>