Coppermodified hexagonal mesoporous silica (Cu-HMS) was in situ prepared with sol-gel method. The structure and the performance of Cu-HMS were characterized by XRD, TG-DTA, ESR, UV-Vis, FT-IR, ESEM, EDS and N₂ adsorptiondesorption isotherms. Based on bacteriostasis experiments of E. coil, S. aureus, B. subtilis and G. bacillus, the antibacterial ability of the sample was also investigated. The results show that the particles of Cu-HMS look like regular thallus, the specific surface area is 533m²/g, the average pore size is 3.6nm, and the copper ions are presented in framework of the sample, especially. The sample has favorable mesoporous structure, thermal stability and ultraviolet-visible-light absorption ability. Furthermore, The bacteriostasis experimental results show that Cu-HMS has favourable and steady antibacterial ability. When the dosage of Cu-HMS is 20mg/L, the bacteriostasis ability may be visibly detected in 12h, while the dosage is up to 200mg/L, E. coil, S. aureus and B. subtilis may be killed after 24h.