Diamond bit technology patent documents in China from 1985 to 2013 are collected and sorted. The applicant type distribution, patent maintenance period, the technology field and the patent legal status are analyzed and compared with the overall patent level in China. The results show that the applications of diamond bit technology patent have been greatly increased in China in recent years, domestic applicants have the absolute superiority in the patent number, the main application fields are geology (mining), petroleum & natural gas and the construction industry. It is balanced for the applicant's technical capacity and there is no monopoly technology encirclement, but the patent type distribution is uneven with short maintenance period and service life. Some patent strategies of diamond bit technology are discussed.