duration of stay?

If you apply for a 6 months double-entry business visa or 6 months multiple-entry business visa, you have to exit China when the Duration of Each Stay will be used out. For example, on your visa, it writes Duration of Each Stay 030 Days After Entry, you have to exit Mainland China when you stay in China for 30 days.

If you apply for a single entry business visa with Duration of Each Stay 180 Days After Entry, you can stay in China for 180 days.

Please refer to https://www.travelchinaguide.com/images/photogallery/2009/chinese-visa.jpg to read about Chinese visa information.