ObjectiveTo explore the effects of modified Gualou Zhishitang combined with piperacillin sodium and tazobactam sodium on the immune function and serum levels of inflammatory cytokines in the patients with stroke-associated pneumonia （SAP， syndrome of phlegm-heat accumulation in lung）. MethodEighty SAP patients with the syndrome of phlegm-heat accumulation in lung were randomized into a control group （40 cases） and a study group （40 cases）. The SAP patients in the control group were treated with piperacillin sodium and tazobtam sodium， while those in the study group were treated with modified Gualou Zhishitang on the basis of the treatment in the control group for 2 consecutive weeks. The clinical therapeutic effects， immune function indexes， inflammation indexes， and lung function of SAP patients in the two groups before and after treatment were determined and compared. ResultAfter treatment， the scores of lesion， pulmonary rales， cough， fever， phlegm color， and constipation in both groups decreased （P<0.05）. After treatment， the ratio of forced expiratory volume in the first second to forced expiratory volume （FEV1/FVC） and forced expiratory volume in the first second as percentage of predicted value（FEV1%） in both groups improved （P<0.05）， and the study group outperformed the control group （P<0.05）. The treatment decreased the neutrophil to lymphocyte ratio （NLR） in the two groups （P<0.05）， and the study group had lower NLR than the control group after treatment （P<0.05）. The serum levels of procalcitonin （PCT） and hypersensitive C-reactive protein （hs-CRP） in both groups declined after treatment （P<0.05）， and the declines were more significant in the study group than in the control group （P<0.05）. After treatment， the study group was better than the control group （P<0.05）. The treatment in both groups elevated the levels of CD3+， CD4+， and CD4+/CD8+ in the peripheral blood and lowered the level of CD8+ （P<0.05）， and the changes were more significant in the study group than in the control group （P<0.05）. The total response rate of the study group was 95.00% （38/40）， which was higher than that （80.00%， 32/40） of the control group （χ2=4.114，P<0.05）. There was no significant difference in the incidence of adverse reactions between the two groups. ConclusionModified Gualhou Zhishitang combined with piperacillin sodium and tazobactam sodium demonstrates a significant therapeutic effect on the SAP patients with the syndrome of phlegm-heat accumulation in lung. This therapy can mitigate the clinical symptoms， improve the lung function， lower the serum levels of inflammatory cytokines， and improve the immune capacity， with high safety.