Sage 50 is bi-lingual as in both English and French. If you want invoices in Chinese you would have to prepare them through a different program like Excel.

Technically what Alwyn is saying is true.  The program does not handle directly running in languages other than English and French.  However, I have helped setup a company for communication of information in German and English.  I also told one person how to do this for Spanish but was not involved in the setup.  They specifically wanted to use the Canadian version of Simply Accounting and didn't want the US version for the Spanish option.

There is no way to have the running of the program display Chinese characters for menu text etc, only French and English.

If you activate the French and English under Setup, Settings, Company, Features, then you may be able to use any of the French fields for Chinese.  I am not familiar with the language character set to know if all characters will display and print as they should without error, so please do some testing first.  If you look through the Knowledgebase, you may find some articles that discuss some problems with the program if Windows is set to a Chinese language setting I think, but I would have to go back and reread the articles myself to understand the issues.

However, you can enter any other language inventory and service descriptions in the French boxes, and they will display/print on the invoices if you set the customer to be French.

You will have to use the internal Forms Designer to change the column headers and other text as applicable on your invoice to use the French settings but entering the Chinese language characters as applicable.