Abstract: Objective To evaluate the effect of therapy of highly agg lutinative staphylococci (HASL) plus cisplatin (DDP) in the treatment of maligna nt pleural effusion in the advanced lung cancer. Methods 64 cases wit h malignant effusions were randomly classified into two groups.32 cases in the H ASL group were treated with HASL plus DDP intrapleural injection.32 cases in the control group were with DDP intrapleural injection. Results Clinical effective rate of the reduction of the volume of pleural effusions in HASL grou p was 71.9%，which significantly higher than the effective rate (43.8%) in con trol group (P<0.01). Conclusion Combination therapy of HASL plus DDP can effectively control the pleural effusion in advanced lung cancer,improv e the life quality of the patients and lower the toxicity of side effects in che motherapy.