Objective To evaluate the short-term effect and safety of endoscopic pyloromyotomy for congenital hypertrophic pyioric stenosis(CHPS).Methods Twelve infants,including 8 boys and 4 girls,mean age(57.5±14.4)days,who were diagnosed as CHPS,underwent endoscopic pyloromyotomy by using an ultra-thin gastroscope.Incisions were made from the duodenal to the antral side of the pylorus by an endoscopic electrosurgical sphincterome or a needle knife.Results These 12 patients underwent 13 endoscopic operations.Vomiting ceased in 1-10 days in 11 cases,of which one patient's vomiting was recurrent 35 days after the first procedure,which was improved 10 days later after another endoscopic operations.Another one did not stop vomiting because of cytomegalovirus hepatitis,whose symptoms were relieved after secondary treatment.No complications were observed except for minor melena in one case after the therapy.Conclusion Endoscopicall pyloromyotomy in CHPS is effective and safe in short-term follow-up.