Question:When exporting document to a pdf file, it does not support Chinese character. 

Answer:
The reason you cannot display chinese character in PDF is due to the font type used in Xin Inventory Report Designer is not supported in PDF format. 
The solution is:

1. You need to create your own template. To learn how to create your own template, please visit http://www.xininvoice.com/invoice-software-customize-invoice-template.html
2. In the Report Designer, choose the text object which you want to display chinese character, in the Property Grid on the bottom right corner, set the font property, choose the font type as "Arial Unicode MS". Please refer to attached Reply1jpg.
3. Save this template and print your invoice with this template.