ObjectiveTo evaluate the optimal standard for detecting coagulase test of Staphylococcus with slide method.MethodsSeventy strains of Staphylococcus spp. isolated  from clinic were studied, Staphylococcus coagulase gene were detected with PCR, Staphylococcus aureus were rapidly detected with latex agglutination test, Staphylococcus coagulase were detected with test tube and slide methods respectively. The species of bacteria were identified by VITEK-Ⅱautomatic analyzer. ResultsAmong 70 strains of Staphylococcus spp., 56 strains were  positive Staphylococcus coagulase gene with  PCR; the same 56 strains were also positive with latex agglutination test; 54 of which were positive with tube test method, 2 strains were false negative; strong positive were detected with slide method, all these 56 strains were identified as Staphylococcus aureus by VITEK-Ⅱ automatic analyzer (the same as PCR results). The other 14 strains were Staphylococcus haemolyticus. The judge of positive of coagulase test with slide method was according to coarse granule or apparent floccule agglutination, the accuracy rate was 80.00%, false positive rate was 20.00%. ConclusionThe optimal standard of  positive results with slide method are as follows: plasma appears apparent ball-like agglutination within 10 seconds, fluid in background should be clear, and there is no agglutination when bacteria strains are mixed in physiological saline.