Objective To explore the best operative time of laparoscopic cholecystectomy for acute cholecystitis, and analyze the causes of laparotomy. Methods The clinical data of 82 cases of laparoscopic cholecystectomy in the Department of General Surgery, the Eighth People's Hospital of Taiyuan from January 2014 to July 2018 were retrospectively analyzed.According to the onset to operation time, the patients were divided into four groups: group A (21 cases, the onset to surgery time was within 48 h), group B (26 cases, the onset to surgery time was 48-72 h), group C(19 cases, the onset to surgery time was>72 h-1 week), group D (16 cases, the onset to surgery time was more than 1 week). The operative time, intraoperative blood loss, conversion of abdominal cavity and complication rate were compared, and the risk factors of conversion to laparotomy were analyzed. Results The open abdominal rates of group A-D were 4.76%(1/21), 19.23%(5/26), 26.32%(5/19) and 18.75%(3/16), respectively.The rate of open abdomen in group C was the highest, which of group A was the lowest.There were statistically significant differences between group A and the other three groups (χ2=3.635, 4.181, 3.682, 3.552, 3.448, all P<0.05). Single factor analysis showed that the laparotomy was related to the enlargement of the gallbladder, the thickness of the gallbladder, and the time of operation (all P<0.05). The analysis of multiple factors showed that the thickness of the gallbladder wall more than 6 mm[OR=1.310 (95% CI: 0.681-1.264), P=0.001], the time of operation more than 48 h[OR=2.672 (95% CI: 0.261-0.961), and P=0.000] were independent risk factors for transabdominal surgery of acute cholecystitis laparoscopy. Conclusion Laparoscopic surgery within 48 hours of acute cholecystitis can reduce the risk of transabdominal surgery.The thickness of the gallbladder and the timing of the operation are independent risk factors affecting the transabdominal operation. Key words: Cholecystitis, acute; Cholecystectomy, laparoscopic; Operative timing; Factor analysis, statistical