In order to verify the possible anti-inflammatory activity and their potency of ofloxacin and Tanshinone II a, the effects of different concentrations of ofloxacin, Tanshinone II a and hydrocortisone on human leukocyte migration in vitro were investigated employing agarose migration technique in which f-Met-Lea-Phe was served as chemotactic factor. The results showed that all the three agents could inhibit migration of leukocytes remarkably. The effects were concentration-dependent with excellent linear relationship. The IC50 were: Tanshinone II a 0.46 microgram/ml, ofloxacin 0.63 microgram/ml, and hydrocortisone 46.52 micrograms/ml respectively. The results indicated that Tanshinone II a was the most potent agent for inhibiting migration of human leukocytes in vitro and the hydrocortisone was relatively less potent.