Thermal cycling tests of TATB based polymer bonded explosives (PBX) samples are undertaken at the scope from －40～75℃. Their dimensions, mechanical properties and detonation performance are also tested before and after the thermal cycling test. The results show that the dimension of TATB based PBX increases with the increasing of cycle number, but the rate of dimension-growth reduces obviously. Because of the surface de-bonding during the thermal cycling test, its modulus, strength and creep properties decrease a little after thermal cycling test. Owing to the void growth during the thermal cycling test, its shock sensitivity increases, but its detonation velocity keeps no change.