The Report function cannot show Chinese letter

The Report function cannot show Chinese letter

Hi,
My company has some chinese customer and the customer name was key into the contact in Chinese, But when i run the report, such as report for invoice detail and exported as a PDF file, i found that all Chinese customer name cannot be showed. i guess it is the font issue but this might also be a fix template issue( i cannot find any setup to alow me to edit a report template like what i did in invoice, estimate etc.)

please can you help me here?
Below picture is a capture from a PDF invoice detail report, and invoice no. 0114 customer name is chinese but it shows blank

best regards and thanks
Roman