Abstract: Objective To study the manipulation,feasibility and safety of natural orifice translumenal endoscopic cholecystectomy in animal models. Methods Ten mongrel dogs were involved in this study.Endoscopic gastrostomy,laparoscopy,transumbilical single orifice endoscopic cholecystectomy were performed.The incision on gastric wall was closed and antibiotics were routinely used.The animals were fed with semi-liquid diet.Two weeks after operation,the animals were sacrificed to observe the changes occurred after cholecystectomy. Results Of the 10 dogs,8 survived for 2 weeks after operation with a success rate of 80%（8/10）,1 died during operation,and 1 died 1 week after operation due to abdominal abscess.The average operation time was 80 min（range 40-150min）.Hemostasis was performed 4 times with electric coagulation and once with clips for liver bleeding during the operation.Leakage occurred in the residual end of gallbladder and cystic ducts and was closed with clips.The incision was completely healed with no abdominal abscess in those that survived for 2 weeks after operation. Conclusion Mongrel dogs can be used as the model of translumenal cholecystectomy in humans.Transumbilical single orifice endoscopic cholecystectomy is feasible and relatively safe.Surgical instruments cannot meet its requirements and remain to be developed.