The present study evaluated that responses of peripheral and bone marrow depends on the frequency of recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration in dogs. The rhG-CSF has been revealed that have a beneficial effect for dogs with myelosuppression secondary to chemotherapy or radiation but there were no studies about the frequency of administration in dogs. In this research, rhG-CSF was administrated $5{mu}g/kg$ subcutaneously for each two-dogs group as follows: (1) every day for trial, (2) every other day for trial, (3) every third day for trial. The peripheral blood analysis including direct microscopic differential counts of one hundred cells was performed every day. Bone marrow aspiration was performed before administration of rh G-CSF, on the day of 0, 3, 9 and when the WBC counts were decreased within the normal range (day 12 or 13). Rh G-CSF was well-tolerated and showed no side effects in all dogs. According to the present study, $5{mu}g/kg$ administration of rhG-CSF have cell-specific, frequency-related effect on bone marrow and peripheral blood. Furthermore, the effects of rhG-CSF administration on bone marrow sustained during the study and prolonged at least 3 days after discontinuing of rhG-CSF treatment.