Abstract： Objective： To observe the clinical effect of Simo tang oral liquid combined with conventional therapy on neonatal abdominal distension. Methods：A total of 160 neonates with abdominal distension were selected as the research objects，and divided into observation group and control group by random number table method，80 cases in each group. The control group was given conventional therapy，and the observation group was additionally given Simo tang oral liquid based on the treatment of the control group. Both groups were treated and observed for two weeks. The rate of weight gain in both groups during the treatment was recorded， and the clinical effect was observed. The levels of intestinal flora including enterobacter and lactobacillus， serum motilin(MTL) and substance P were compared between the two groups before and after treatment. Results：During the treatment，the average rate of weight gain in the observation group was higher than that in the control group(P＜0.05). The total effective rate was 98.8% in the observation group and 88.8% in the control group，the difference being significant(P＜0.05). After treatment， the level of enterobacter in both groups was decreased when compared with that before treatment(P＜0.05)， and the level of lactobacillus was increased(P＜0.05)； the level of enterobacter in the observation group was lower than that in the control group(P＜0.05)，and the level of lactobacillus was higher(P＜0.05). After treatment，the levels of serum MTL and substance P in both groups were increased when compared with those before treatment(P＜0.05)， and the above two levels in the observation group were higher than those in the control group(P＜0.05). Conclusion： Simo tang oral liquid combined with conventional therapy in the treatment of neonatal abdominal distension can promote the secretion of MTL and substance P， improve intestinal flora， alleviate clinical symptoms，and promote the weight gain of newborn.