diff --git a/book/contents/basic/compound-type/string-slice.md b/book/contents/basic/compound-type/string-slice.md
index 3657440f..45e0125b 100644
--- a/book/contents/basic/compound-type/string-slice.md
+++ b/book/contents/basic/compound-type/string-slice.md
@@ -81,7 +81,7 @@ let slice = &s[0..len];
 let slice = &s[..];
 ```
 
->在对字符串使用切片语法时需要格外小心，切片的索引必须落在字符之间的边界位置，也就是UTF8字符的边界，例如中文在UT8中占用三个字节,下面的代码就会崩溃:
+>在对字符串使用切片语法时需要格外小心，切片的索引必须落在字符之间的边界位置，也就是UTF8字符的边界，例如中文在UTF8中占用三个字节,下面的代码就会崩溃:
 >```rust
 >  let s = "中国人";
 >  let a = &s[0..2];