Hi,

1. The characters overlaps each other and can not be set size.

The is a mini example.

\definefont[song][name:simsun at 12pt]
\starttext

\song 测试

\stoptext

The attachment is its output.

2. the cid fonts cause MkIV gives a waring as following:

  LuaTeX warning: lua-loaded font [44]
(/usr/share/fonts/adobe/AdobeSongStd-Light) has no characters!


-- 
Best regards,

Li Yanrui (李延瑞)