In this paper, a three-dimensional precise conformal radiotherapy treatment planning system based on a cobalt-60 teletherapy unit is introduced. With the help of additional precise target localization and conformal field-shaping devices, the TPS can greatly improve the performance of conventional cobalt-60 teletherapy units in precise target localization, radiotherapy planning and dose delivery. The clinical practices show that the TPS has advantages of reliable precision and an affordable price , and it is urgently needed in our country.