Purpose: This study aimed to identify factors influencing intra-operative core body temperature (CBT), and to develop a predictive model for intra-operative CBT in laparoscopic abdominal surgery. Methods: The prospective observational study involved 161 subjects, whose age, weight, and height were collected. The basal pre-operative CBT, pre-operative blood pressure, and heartbeat were measured. CBT was measured 1 hour and 2 hours after pneumoperitoneum. Results: Explanatory factors of intra-operative hypothermia (<36˚C) were weight (β=.361, p<.001) and pre-operative CBT (β=.280, p=.001) 1 hour after pneumoperitoneum (Adjusted R2=.198, F=7.56, p<.001). Weight was (β=.423, p<.001) and pre-operative CBT was (β=.206, p=.011) 2 hours after pneumoperitoneum (Adjusted R2=.177, F=5.93, p<.001). The researchers developed a predictive model for intra-operative CBT (˚C) by observing intra-operative CBT, body weight, and pre-operative CBT. The predictive model revealed that intra-operative CBT was positively correlated with body weight and pre-operative CBT. Conclusion: Influence of weight on intra-operative hypothermia increased over time from 1 hour to 2 hours after pneumoperitoneum, whereas influence of pre-operative CBT on intraoperative hypothermia decreased over time from 1 hour to 2 hours after pneumoperitoneum. The research recommends pre-warming for laparoscopic surgical patients to guard against intra-operative hypothermia.