Abstract:In order to study the anti-microbial effect of the six kinds of tea under the same processing raw materials, the spring tea fresh leaves of C.sinensis cv.Bixiangzao were processed into fixation of fresh leaves, green, yellow, dark, white, oolong, and black tea. The anti-microbial activity against Staphylococcus aureus (S. aureus), Escherichia coli (B. subtilis), Escherichia coli(E. coli), Aspergillus niger,(A. niger), Saccharomyces cerevisiae (S. cerevisiae) of 7 samples were determinded by the Oxford cup method. The Minimum inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) of 7 samples were determined by the method of two times dilution using the microplate of the 96 hole. Experimental results showed that 7 samples had inhibition effect of bacteria and had no obvious effect of A. niger and S. cerevisiae. The antibacterial circle size of 7 samples of S. aureus, B. subtilis, and E. coli showed that the trend of antimicrobial activity was: fixation of fresh leaves>green>yellow>dark>white>oolong>black tea. The MIC showed that the trend of antimicrobial concentration was: black tea>oolong, white tea>dark, yellow, green tea, fixation of leaves. The MBC showed that the trend of antimicrobial concentration was: black tea>oolong, white, dark, yellow tea>green tea, fixation of leaves. The antimicrobial activity of green tea and black tea was significantly different from other teas (P<0.05).