Objective::To observe the clinical efficacy of modified Shenling Baizhusan on stroke-associated pneumonia (SAP) with lung-Qi deficiency syndrome and its regulatory effect on inflammatory factors and immune function. Method::One hundred and ten patients were randomly divided into control group (55 cases) and observation group (55 cases) by random number table. Patients in control group got piperacillin sodium and tazobactam sodium for slow intravenous injection, 4.5 g/time, 3 times/days, for 7-10 days, and new antibiotic was chose by drug outcomes, ambroxol hydrochloride injection for low intravenous infusion, 30 mg/time, 2 times/days, for 10 days, and nutritional support and symptomatic comprehensive treatment. In addition to the therapy in control group, patients in observation group were added with modified Shenling Baizhusan, 1 dose/day, for 10 days. And scores of pulmonary infection (CPIS), time of CPIS<6 time of disappearance of cough, time of recovery of temperature, time of recovery of leukocyte, and time of disappearance of lung rales were recorded. And before and after treatment, lung-Qi deficiency syndromes were scored, and levels of procalcitonin (PCT), γ-interferon (IFN-γ), tumor necrosis factor-α (TNF-α), high-sensitivity C-reactive protein (hs-CRP), immunoglobulin A (IgA), immunoglobulin G (IgG), immunoglobulin M (IgM), T Lymphocyte subsets (CD4+, CD8+ and CD4+ /CD8+) were all detected. Result::By rank sum test, the clinical effect in control group was better than that in control group (Z=2.106, P<0.05). Scores of CPIS and lung-Qi deficiency syndromes were lower than those in control group (P<0.01). And time of CPIS<6, time of disappearance of cough, time of recovery of temperature, time of recovery of leukocyte, and time of disappearance of lung moist rales were all shorter than those in control group (P<0.01). And levels of PCT, TNF-α, hs-CRP and CD8+ were lower than those in control group (P<0.01, P<0.05), while levels of IFN-γ, IgA, IgM, CD4+ and CD4+ /CD8+ were all higher than those in control group (P<0.01, P<0.05). Conclusion::In addition to the comprehensive anti-infection therapy, modified Shenling Baizhusan can control the degree of illness, alleviate symptoms, regulate the expressions of inflammatory factors, increase the immune function of the body, and improve the comprehensive efficacy.