Objective To observe the therapeutic effect and mechanism of Xiaopi Granules（granules to disperse epigastric fullness syndrome）on chronic atrophic gastritis（CAG）with atypical hyperplasia（ATP）.Methods Sixty male wistar rats were randomized into normal group

model group

natural recovery group

Xiaopi Granules group and vitacoenzyme group

with 12in each.The rat models were replicated by methods of pylorus spring insertion and high-salt hot paste for 16weeks.The rats in the normal group and the model group were executed after 16weeks of modeling.The rats in the Xiaopi Granules group were intragastrically administrated with 0.5ml/（100g.d）of Xiaopi Granules one week after surgery.The rats in the natural recovery group were intragastrically administrated with 0.5ml/（100g.d）of distilled water after 16weeks of modeling.The rats in the vitacoenzyme group were intragastrically administrated with 0.5ml/（100g.d）（0.04g/ml）of vitacoenzyme suspension one week after surgery.The intragastric administration was given 6times weekly for 12 weeks in all groups.The expressions of proliferation cell nuclear antigen（PCNA）

Bcl-2 and Bax in the gastric mucosa were detected with immunohistochemical method.Results The positive expressions of PCNA and Bcl-2were significantly increased and the positive expression of Bax was significantly decreased in the model group and the natural recovery group compared with the normal group（P< 0.05 or P<0.01）.Compared with the model group

the positive expression density of PCNA was significantly different in all other groups（P<0.05 or P<0.01）.The positive expression density of PCNA in the Xiaopi Granules group was significantly lower than that in the natural recovery group（P<0.05）and has no significant difference with the vitacoenzyme group（P> 0.05）.The expression of Bcl-2was reduced and the expression of Bax was increased significantly（P<0.01）in the Xiaopi Granules group as compared with those in the model group

but there was no significant difference as compared with the vitacoenzyme group（P>0.05）.Conclusion Reduction of expression of PCNA and Bcl-2

and increase of expression of Bax in gas-tric mucosa in precancerous lesions of model rats might be relevant to its effect of regulating the apoptosis and proliferation of mucosal cells.