Using Chinese in TeXShop

TeXShop is the mac os version of TeXLive.
Using Chinese here is different from that in CTeX. I don't know exactly what happens yet, but I do know one way to use Chinese under TeXShop environment, which is followed:

\usepackage{CJKutf8}
\begin{CJK}{UTF8}{gbsn}
...
\end{CJK}