Abstract: In order to study the protective effects and mechanism of Enteromorpha polysaccharides( EP) of Jiangsu province on the ethanol-induced gastric mucosal lesion of rats in vivo,total 60 Wistar rats were randomly divided into EP groups(100,200,400 mg/kg),negative control group,model group,and positive control group(Omeprazole,300 mg/kg),i.e. 10 cases in each group. The model of acute gastric mucosa lesion was induced with absolute alcohol. After treated with EP with 7 days,the general and pathological integral of gastric mucosa lesion were observed. The levels of gastric juice volume,total titrable acidity,mucin,MDA,GSH-Px,IL-1β,TNF-α content,SOD and COX-2 activity were measured. Results :The gastric lesions were significantly reduced by all doses of EP(p <0.01). EP administration in high doses markedly reduced the volume of gastric juice( p < 0. 05), increased the GSH- Px tissue levels, and reduced the levels of pro-inflammatory markers IL- 1β and TNF- α( p < 0. 01). Moreover, all doses of EP significantly decreased the elevated MDA and COX-2 tissue levels(p<0.01 or p<0.05),whereas increased the SOD and mucin content(p <0.01 or p <0.05) in model rats. In a conclusion,these results suggested that EP could exert a beneficial gastroprotective effect through their anti-oxidant and anti-inflammatory properties.