Gastric ulcer is a common gastrointestinal disease caused by excessive gastric acid secretion, which has been recognized as one of the most common causes of morbidity and mortality in the world. The skin of Rana chensinensis is rich in collagen and many previous studies have shown that it has certain bioactivity. Therefore, we extracted and purified collagen with a molecular weight less than 10000 Da from the skin of Rana chensinensis, and studied its gastric protective mechanism through the model of ethanol-induced gastric ulcer in Balb/c mice. The results showed that through macroscopic observation and significantly reduced ulcer index, it was proved that PCRCS could protect gastric mucosa and alleviate the damage of ethanol to gastric mucosa. PCRCS reduced ethanol-induced oxidative stress by boosting depleted SOD levels and dramatically lowering MDA levels, as well as significantly reducing lipid peroxidation. Additionally PCRCS (Protein Chinese Rana chesinensis Skin) additionally decreased the launch of inflammatory mediators TNF-α and IL-6 and more desirable the content material of protective elements NO and PGE2 in gastric mucosa. Based on these findings, we believe that PCRCS has potential stomach protective effects on ethanol-induced gastric ulcer, which may be achieved by inhibiting oxidative stress and stomach inflammation.