The greater omentum was dissected by using ultrasound knife along greater curve 2 cm away from Pylorus, and the adhesion between the posterior wall of the stomach and the pancreas was fully dissected until the gastric fundus, the left foot of the diaphragm and the left side of the esophagus were exposed. 36F gastric tube was inserted along the small curvature of the stomach until it reached the antrum. the sleeve shaped stomach was dissected 4~6 cm away from the pylorus by using linear staplers according to the thickness of gastric wall. The cutting line was 1cm away from the edge of the gastric tube, and 1~2 cm away from the left edge of the esophagus at gastric fundus. The greater omentum could be sutured at the incision edge of the stomach, then as following to remove the gastric tube, to clean the abdominal cavity, to enlarge the main operation hole, to take out the excised gastric tissue, to place the drainage tube at the left diaphragm foot, finally to close 10 mm and 12 mm Trocar holes by non-absorbable suture.