To get the buziness VISA, delegates may need an invitation letter, here is the important information regarding invitation letters (please read):
以下为您介绍关于签证的一些信息。
Conference participants may need a Chinese visa
to enter China. Specifically, those who are not
Chinese citizens, except passport holders from
Singapore, Brunei, and Japan, need a Chinese visa.
Participants can apply for a visa at the Chinese
embassy or consulate in the region in which they
live. To avoid uncertainty, participants will be
advised to apply for a visa as early as possible. It
is recommended that they apply for a Chinese visa at
least 1 month in advance.
For most attendees, it is easier to apply for a
Tourist ("L") visa; an invitation letter is NOT
required for obtaining a Tourist visa.