Objectives To study the inhibitory activity of internal irradiation of interventional radionuclide 188Re in thermosensitive chitosan on mouse transplanted tumor H22 ( liver cancer) . Method The tumor-bearing mice were divided into 7 groups randomly，including model control，188Re(0. 1mCi) group，188Re-S(0. 1mCi) group，188Re + CS(0. 1mCi)group，188Re + CS (0. 2mCi) group，188Re-S + CS 0. 1mCi) and188Re-S + CS(0. 2mCi) group. The mice tumor was injected with corresponding reagent respectively，and the inhibitoy rate of tumor was observed after administrated. Results The growth of tumors in 188 Re + CS group and 188 Re-S + CS group was slowed. the tumor inhibitory rate reached the highest level after 6 days therapy，which respectively was 67. 35% and 67. 81% . Conclusions Internal irradiation of interventional radionuclide 188 Re in thermosensitive chitosan had the effect of inhibitory mice liver cancer.