Objective To observe the effect of Renzhu Jianpi Liqi Granules on gastric accommodation of rats with functional dyspepsia（FD）and explore its mechanism. Methods In vivo experiment: 75 SD rats were randomly divided into normal group, model group, as well as high-dose group, medium-dose group and low-dose group of Renzhu JianpiLiqi Granules. Rats with FD were developed by combining neonatal iodoacetamide-treatment and adult tail-damping. The normal group and the model group were given normal saline by gastric lavage, and the high, medium and low dose groups of Renzhu Jianpi Liqi Granules were given corresponding doses of Renzhu Jianpi Liqi Granules by gastric lavage respectively. After the detection of 3-hour food intake, the gastric accommodation of rats in each group was measured by electronic constant voltage device. In vitro experiment: The proximal gastric muscle strips of rats were prepared in order to detect the effects of Renzhu Jianpi Liqi Granules on the tension ofstrips of rats. Results In vivo experiment showed that the 3-hour food intake in the model group was significantly lower than that in the normal group（P<0.01）; the 3-hour food intake of the high and medium dose groups of Renzhu Jianpi Liqi Granules was significantly higher than that of the model group（P<0.01）; the gastric accommodation of rats in the model group was significantly lower than that of in the normal group（P<0.05）; the gastric accommodation of rats in the high, middle and low dose groups of Renzhu Jianpi Liqi Granules was higher than that in the model group（P<0.05）. In vitro experiment showed that Renzhu Jianpi Liqi Granules（300, 3 000 and 6 000 μg/mL）could significantly reduce the tension of proximal gastric muscle strips of rats; L-NAME could partially inhibit the effect of Renzhu Jianpi Liqi Granules on the reduction of smooth muscle tension. Conclusion Renzhu Jianpi Liqi Granules can improve gastric accommodation in FD rats. Its action mechanism may be related to regulating the synthesis and release of NO and reducing the tension of proximal gastric smooth muscle.