The thesis selected nano-titanium dioxide compound silver antibacterial and thulium compound nanometer antibacterial as research object, whose application are the widest. Their characters to resist staphylococcus aureus, colon bacillus and Candida albicans were studied by qualitative analysis, quantitative analysis and TEM. The study indicated that nano-titanium dioxide compound silver antibacterial is dissolving antibacterial and thulium compound nanometer antibacterial is non-dissolving antibacterial. These two kinds of antimicrobials both have a minimal inhibitory concentration of the three kinds of bacteria. Different nano-antimicrobials act on bacteria, the changes of bacteria’s shape are different, and this indicates the mechanism of action is different.