Objective: To evaluate the treatment effect of high-energy ultra-pulse CO_2 laser on flat warts. Methods: 192 patients with flat warts were divided into observation group( high-energy ultra-pulse CO_2 laser treatment group) and control group( cryotherapy group) equally and randomly. All the cases received intramuscular injection of BCG polysaccharide and nucleic acid. The efficient,the average treatment times and side-effect were compared between the two groups. Results: The efficient of observation group( ...