The first gamma irradiator was constructed in China in the late of 1950s, through nearly half centurys development, now there are total 120 gamma irradiators with total design capacity more than 100MCi in operation in China.The total source activity in use is about 45 MCi, up to 13% of the total activity in used of whole world.The gamma irradiators have been the main facilities for food irradiation in China, and the gamma irradiators in China have been a very important part of the world radiation processing industry now.