To apply for a visa for China, you need to complete an
application form attached with your recently-taken color
photo, prepare a valid passport, and submit them along with
other supporting documents to China Visa Application Service
Center, Chinese embassy or consulate which is in charge of
your residence area.
The best time to apply for China visa is one or two months
before your departure date. Usually, a China visa is valid for
only three months from the date of issue, which indicates that
the earliest time you can apply is three months before your
departure.
For most attendees, it is easier to apply for a Tourist ("L")
visa; an invitation letter is NOT required for obtaining a
Tourist visa. For more information, please check with local
Chinese Embassy in your country.