Objective To observe the effect of Yiqi Qingre Formula（Formula for Reinforcing Qi and Clearing Heat） on histopathological changes of gastric mucosa in nude mice infected with helicobacter pylori（Hp） type Ⅰ.Methods Totally 80 male nude mice were randomly divided into 4 groups:model group

Huangqin（Scutellaria） group

Huangqi（Astraglus） group and Yiqi Qingre Formula group

with 20 nude mice in each group.Each nude mouse was treated accordingly with gastric feeding with 0.2ml/10g Chinese medicine or normal saline everyday.On the fourteenth day

all mice were given 108cfu/ml Hp liquid through gastric feeding

1.3ml for each mouse.At the end of the second week

The rats were killed for observing the body weight

stomach coefficient

Hp infection and pathological condition of gastric mucosa.Results Comparing with the model group

Huangqi group and Yiqi Qingre Formula group were less reduction of body weight（P<0.05）

gastric coefficient in Huangqi group diminished（P<0.01）.Hp infection rates of Huangqin group

Huangqi group and Yiqi Qingre Formula group was 45.00%

47.06% and 35.29% respectively

incidence rates of superficial gastritis being 70.00%

58.82% and 64.7% respectively

lower than that of the model group（P<0.05）.Conclusion Yiqi Qingre Formula has the function of killing Hp type Ⅰ and can improve the pathological changes of gastritis in gastric mucosa.