Abstract: Objective 　To investigate the safety, feasibility and adverse reaction of combination of G-CSF and GM-CSF in patient s with Ⅱdegree and above arrest of bone marrow caused by chemotherapy. Methods 　84 patients with definite malignant tumor and Ⅱdegree and above arrest of bone marrow caused by chemotherapy were enrolled into a single-blinded and random study : G-CSF group ( G group, n = 28, G-CSF 150μg/ d subcutaneous injection), GM-CSF : group ( GM group : n = 28, GM-CSF 150 μg/ d subcutaneous injection), combination drugs group ( G/ GM group, n = 28, GM-CSF 75 μg/ d and GM-CSF 75 μg/ d subcutaneous injection) . Observation items : (1) the days of WBC normalization af ter CSF application ;(2) WBC count after 48 hours withdrawal of CSF ; (3) PL T count af ter 48 hours withdrawal of CSF ; (4) incidence rate of adverse reaction. Results 　Leukcocyte count in three groups increased. The days of WBC normalization in GM group were longer than that in G group and G/ GM group ( P < 0. 05) . WBC count af ter 48 hours withdrawal of CSF in GM group and G/ GM group was obviously more than that in G group ( P < 0. 05) . Incidence rate of adverse reaction in three groups was approximate and there was no significant difference between groups. Conclusion 　Combination of G-CSF and GM-CSF was an effective and safe treatment to be applied in patient s with arrest of bone marrow caused by chemotherapy, and it could reduce the defect of single application.