To observe the clinical effects of modified Maxing Shigan Decoction on pulmonary community-acquired pneumonia with phlegm-heat obstructing lung,and to explore its effect on the immune system of patients.Methods:From March 2017 to March 2018,80 patients with pulmonary pneumonia phlegm-heat obstructing lung in the Department of Integrated Chinese and Western Medicine of Suizhou Central Hospital were randomly divided into a control group and an observation group,each of 40 cases according to random number table method.The 2 groups were both treated with routine western medicine in the Department of Integrated Chinese and Western Medicine.On the basis of the routine treatment,the observation group was treated with modified Maxing Shigan Decoction.The 2 groups were treated with Maxing Shigan Decoction for 10 days as a course.After the course of treatment,the total clinical efficacy,clinical symptoms,lung function,T lymphocyte subsets,TNF-α and IL-6 levels were compared between the 2 groups.Results:1)The total effective rate was 95.0% in the observation group and 75.0% in the control group,and there was significant difference between the 2 groups(χ2=4.05,P<0.05); 2)After the treatment,the scores of TCM syndromes in the 2 groups decreased,and there was significant statistic difference between the 2 groups(P<0.05).3)After the treatment,the disappearance time of cough,sputum,fever and lung rale symptoms was shorter than that of the control group,and the difference was statistically significant(P<0.05); 4)After the treatment,the lung function(FEV1,PEF)and blood gas analysis(pH,PaCO2,PaO2)of the 2 groups improved,and the difference was statistically significant(P<0.05).5)After treatment,the levels of CD4+,CD4+/CD8+ significantly increased,and the levels of CD8+,TNF-alpha and IL-6 decreased in the 2 groups.There was a significant statistic difference between the 2 groups(P<0.05),and the improvement in the observation group was more obvious than that in the control group and the difference was statistically significant(P<0.05).Conclusion:Maxing Shigan Decoction has an ideal effect on pulmonary pneumonia with phlegm-heat obstructing lung,and its mechanism may be related to improving the immune function of patients.