More than 50,000 men have received spermatic duct injections, a new method of male sterilization, in densely populated Sichuan Province since 1972. The new method is to inject 0.02 milliliters of a phenol mixture into the spermatic duct and to block the duct for 1.5 centimeters. The method takes less than 10 minutes, which involves no surgical operation. The method was devised by Li Chunqiang, a surgeon at the Chongqing No. 1 workers' hospital, who is also deputy director of the city's research institute on family planning. Examinations of the seminal fluid of 1629 men who had the injections showed that 92.04% of their sperm disappeared. The method has been shown to be 90.95% effective. This method is simple, safe and reliable, and less complicated than vasectomy. It reduced hematoma, infection and causes less damage to surrounding tissue.