One gram of SM powder consists of 167.8 mg of Coptidis Rhizoma Pulveratum, 250 mg of Cinnamomi Cortex Pulveratus, 67.1 mg of Foeniculi Fractus Pulveratus, 33.6 mg of Caryophylli FLos Pulveratus, 82.1 mg of Zingiberis Rhizoma Pulveratus, 3.4 mg of Zanthoxyli Fructus Pulveratus, and 396 mg of Glycyrrhizae Radix Pulberata. SM powder (2 g/kg, i.d.) significantly inhibited gastric secretion in pylorus-ligated rats and the development of Shay ulcers and indomethacin-induced gastric lesions. The mechanism of the anti-lesion activity of SM powder appears to be due to its antisecretory effect. SM powder also markedly inhibited ethanol- or NaOH-induced gastric lesions at doses (30 or 100 mg/kg) which had little effect on gastric secretion. SM powder appears to have a cytoprotective activity which is unrelated to endogenous prostaglandins. However, SM powder had no effect on water-immersion stress- or aspirin-induced gastric lesions and mepirizole-induced duodenal ulcers. Gentiana Radix Pulverata, used as a reference stomatic, had also an antisecretory effect and anti-lesion activity on Shay ulcers, aspirin-, ethanol- and NaOH-induced gastric lesions. However, it had no effect on water-immersion stress- or indomethacin-induced gastric lesions and mepirizole-induced duodenal ulcers.