Objective Three different staining techniques were used to visualize S180 ascites smear morphology. The results were compared to find a best and simple staining technique showing most clear cytological characteristics. Method S180 ascites smear was stained by H.E. staining, Pap staining and fast staining, and the cell morphology was observed and compared under microscope. Results Among the 3 staining methods, the fast staining was most simple to operate and revealed cellular structures best. There was a best contrast among cytoplasm, nucleus and nucleolus in the smears stained by the fast staining, and the cell structures can be distinguished most clearly. Conclusion The fast staining is better than HE staining and Pap staining in S180 Aseites smear observation.