The database contains 6,607,322 (as of April 2013) Chinese patents after 1985. It covers patents of invention, utility, and design. The database is invaluable for patent information retrieval, patent application, research and design, and product development.
The Chinese State Intellectual Property Office (SIPO) has made the Chinese Patents free searchable and downloable with user interefaces in both English and Chinese at www.sipo.gov.cn. While downloading a patent yourself may be cumbersome, document delivery services through specialists would be a hassle free option.
Beside being free, the official database is actually the most updated.