From the 1st of january 2012 the Chinese Embassy demands that all tourist travellers have to submit an invitation letter from either a company/travel agent in China or the private person the applicant is visiting.
It has to be signed by the person or stamped by the company visited. If the invitation is not possible to acquire, then the applicant has to submit the following 4 documents:

1. Birth certificate
2. Travel plan - Must be written by the applicant and not the by the travel agent. Must contain cities to be visited and dates for the visit. Also it must contain purpose of journey. As a tourist you may write touring. The title of the document must be Travel plan for (applicants name)
3. Copy of Airline ticket and
4. Copy of Hotelbooking