Abstract: This study was to prepare a novel injectable thermosensitive hydrogel system incorporating paclitaxel loaded micelle (PTX-M-P407),and to assess the in vitro drug release profile,tissue distribution and anti-tumor efficacy in Heps tumor-bearing mice.PTX-M-P407 was prepared with cold method.Drug release profile was evaluated with membranes-less method.Tissue distribution and in vivo anti-tumor activity were compared after intratumoral injection of Taxol,PTX-M and PTX-M-P407 in Heps tumor-bearing mice.In vitro drug release was in accordance with Zero order kinetics which was determined by hydrogel dissolution.After intratumoral injection of Taxol,PTX-M and PTX-M-P407,AUCs in tumor were 77.43，127.53 and 935.75 d ·μg/g,and MRTs were 0.76，0.65 and 6.92 d,respectively.In vivo anti-tumor study demonstrated that PTX-M-P407 was superior in impeding tumor growth than other PTX formulations.In conclusion，PTX-M-P407 was a promising intratumoral drug delivery system to enhance anti-tumor efficacy.