The mutagenicity of DA-3030(rhG-CSF)was studied by reverse mutation test, chromosome aberration test and micronucleus test. The reverse mutatuon test in bacteria was performed using salmonella typhimurium strain TA100, TA98, TA1535 and TA1537 with rhG-CSF in any of the concentrations(150, 75, 37.5, 18.75, 9.375 and 4,6875 $mu extrm{g}$/plate), no increase in the number of revertant colonies in each strain was observed, irrespective of treatment with the metabolic activation system(S-9 mix) The chromosome aberration test was carried out using CHL cells, cell line from chinese hamster lung. With 4 doses(75, 37.5, 18.75 and 9.375 $mu extrm{g}$/ml) of rhG-/CSF the cells were treated for 24 or 48 hours in the direct method or for 6 hours followed by 18 hour-expression time in the metabolic activation method. Results of the study showed, by the direct method or metabolic activation method, no trend toward increase in the number of aberrant metaphase. The micronucleus test was carried out using ICR mice at the age of 8 weeks. Three doses(862.5, 1725 and 3450 $mu extrm{g}$/kg) of DA-3030 were admintstered intraperitoneally with single shot and bone marrow cells were sampled at 24 hours after administration. Neither the number of polychromatic erythrocytes with micronuclei nor the ratio of normochromatic erythrocytes to polychromatic erythrocytes increased singinficantly in each dose, compared with a vehicle control. These results indicate that rhG-CSF has not mutagenic potential under the condiions.