Objective：To investigate the in vitro/vivo release of thermosensitive hydrogel containing stromal cel1 derived factor-l（SDF-1） and its influences on hematopoitic tissue. Methods：（1）In vitro release：chitosan-gelatin-glycerol phosphate（CS/G/GP） hydrogel containing SDF-1 which was labeled by 125I was used and gamma counter was applied to measure its in vitro release. （2）In vivo re－lease：125I-labeled SDF-1 was injected to femoral shaft of 18 SD rats and vivo releases were collected from femoral shaft，femoral head，peripheral muscle tissues and offside femoral head and were measured（from the 1st-6th d，3 rats each day）. （3）Bone marrow hematopoiesis：10 SD rats were divided into 2 groups，5 rats in experiment group were injected with 0.1 ml CS/G/GP hydrogel con－taining SDF-1 and 5 rats in control group were injected with 0.1 ml CS/G/GP hydrogel without SDF-1.All 10 rats were killed at the 7th d and their femoral heads were collected to do bone marrow biopsy. Results：In vitro and in vivo release curves were obtained. Hematopoiesis was more active in experimental group than in control group（P<0.05）. There were statistical differences in hematopoi－etic area between the two groups（P<0.05）. Conclusions：CS/G/GP hydrogel containing SDF-1 could maintain stable concentration in femoral head and it could activate bone marrow hematopoiesis.