Abstract: Objective : To investigate the effect of CTX on the ability of bone marrow to release granulocytes and to compare the efficacy of APS and G-CSF. Methods : We detected the expression of CD62L on granulocytes in bone marrow, the serum sCD62L concentration and the peripheral blood white blood cell count in 90 mice at different time points of chemotherapy. All data were statistically analyzed. Results : (1) White blood cell count was reduced on day 7, 10 and 14 after chemotherapy compared with that on day 0. No changes were found in the negative rate of CD62L on granulocytes in bone marrow on day 7 but elevation was observed on day10 and 14. (2) White blood cell count was increased in APS and G-CSF-treated groups after chemotherapy.The negative rate of CD62L on granulocytes in bone marrow was increased simultaneously in the group treat-ed with APS. (3) The range of serum sCD62L concentration was 1.02-1.49μg/ml in the APS group. The con-centration of sCD62L was increased on day 14 in the G-CSF group compared with the APS group. Conclu-sion : The granulocyte releasing function of the bone marrow was impaired on day 7 of chemotherapy in experi-mental mice. APS promotes granulocyte releasing and can help increase white blood cell count in the periph-eral blood, an effect that is mild and sustained. G-CSF promotes the proliferation of granulocytes and the re-lease of immature granulocytes.