Abstract: Objective: To evaluate the efficacy and toxicity of domestic rhGM-CSF, Gening in prevention of leucopenia and neutropenia caused by cancer chemotherapy. Methods: A multicenter, randomized, match and cross-over clinical trial, 65 patients were divided into AB and BA groups and two-cycle treatment were given to each patient.In group AB, combination chemotherapy and Gening were given in the first cycle and combination chemotherapy alone was given in the second cycle, while vice versa in group BA. Results: Geningsignificantly increased the number of white blood cell and the absolute neutrophil count at the nadir, shorten the days with leucopenia and neutropenia of chemotherapy patients with the acceptable the adverse reactionseg. mild or moderate fever, injection site reaction, bone pain, myalgia, asthenia and skin rash. Conclusion: Gening is a valuable adjuvant in cancer chemotherapy.