The different kinds of collagen-Zn complexes were prepared by zinc acetate, zinc chloride, zinc nitrate, and zinc sulfate reacted with collagen protein. Their antibacterial activities have been investigated by MIC method. It was found that the antibacterial activity of collagen-ZnSO4 complex is better than that of others. To obtain a better antibacterial activity, collagen-ZnSO4 complexes with different zinc amount were prepared using zinc sulfate as starting material. These complexes were characterized by FT-IR, XRD, and atomic absorption spectrometry. The results showed that zinc ion could chelate with N-H, C-O, and C=O group in collagen to form the stable complex. Antibacterial activities of collagen-ZnSO4 complexes containing different Zn amount were evaluated against Escherichia coli and Staphylococcus aureus. The results suggested that antibacterial activity increases with the increase of zinc amount.