PDF Invoice Pro magento extension support for Chinese language. Please follow these step to install the Chinese font for the extension..
First you need to download the font package from this url: http://www.vnecoms.com/fonts/Chinese_Font.zip extract the package and upload the app folder to your magento root folder.
After you upload the font package you can use this css to display your Chinese characters.
font: 12px fireflysung;
You should put this css code to the additional css like this:
.chinese_chars{font: 12px fireflysung;}
Then from your PDF template you can use the code like this
<p class="chinese_chars">YOUR CHINESE CHARACTERS HERE</p>
