In order to investigate the strength,structure and cell cytocompatibility of injectable thermosensitive chitosan(CS)/poly(vinyl alcohol)(PVA)composite hydrogel,chitosan hydrochloride solution was transferred to a neutral pH and mixed with different proportions of PVA,then the gelation time and strength of these different hydrogels were tested and spatial structures were observed under a scanning electron microscopy(SEM)after freeze-drying.The cytocompatibility of the hydrogels was evaluated through cytotoxicity test and three-dimensional culture with bone marrow mesenchymal stem cells.The results showed that the CS/PVA solution kept in liquid state at low temperature(0-4℃)and ted into transparent elastomer about 15-20 min at 37℃.Gelation time was prolonged,the strength increased and porous structure became dense with the PVA content increased in the mixed hydrogel.The cytotoxicity grades of these gels were from 0 to 1.Rabbit bone marrow mesenchymal stem cells could survive and proliferate in the gel within 3 weeks,and the gel had good cytocompatibility,it was concluded that thermosensitive CS/PVA composite hydrogel not only has interpenetrating network structure and better mechanical strength,but also has good cytocompatibility,and may be used as an injectable scaffold for tissue engineering.