Does the business letter have to come from a US company for the visa application to China?

Do you visit China for business purpose, if yes, the detail requirements for it may differ in Houston, Los Angeles, or Washington DC,etc. The business letter from US based employer or sponsoring company, and it should introduce on company letterhead your employment status/position held in the company, and the purpose of visit to China. The business letter must also indicate who will be financially responsible for your trip, providing detailed contact information of your visit company in China as well. In addition, it should specify the number of entries and visa validity being requested.