Objective: To evaluate the effect and adverse reactions of combined chemotherapy and XianYu Decoction in the treatment of medium or late stage none-small cell lung cancer(NSCLC). Methods:90 patients with stage Ⅲ~Ⅳ NSCLC were divided randomly into groupA, group B and group C. In group A, 30 patients were treated with XianYu Decoction alone. In Group B(as a control group), 30 patients were treated with chemotherapy alone. In Group C, 30 patients were treated with chemotherapy combined with XianYu Decoction. The effect and adverse reactions of the three groups, including the changes of tumors, the main symptoms of NSCLC, quality of life, body weight, immunity and side-effect, were evaluated after one course of treatment.Results:The complete and partial remission rate(CR PR) of Group C(46. 67%) was higher than Group B(30.00%), but have no significant difference between them(P>0. 05), The complete and partial remission rate of Group A(3. 33%) was lower than Group B and Group C(P0. 05). The Group A had a better effect in the remission of symptoms such as cough, fever, polypnea, debility and anorexia than Group B (P0.05). The Group C had a better effect in the remission of symptoms such as cough, hemoptysis, fever, polypnea and debility than Group B(P0. 05). In group C, CD3  and CD4  increase significantly after treatment (P0.05). XianYu Decoction had no severe adverse reactions. The rate of adverse reactions in Group C were lower than that in Group B,especially in the field of the system of hematology, alanine ami notransf erase (ALT), aspartate aminotransf erase (AST), vomit, blood urea nitrogen(BUN), creatinine(CREA), heart rate, hypersusceptibility, hair, peripheral nerve and skin, there were significant difference(P<0. 05). Conclusion: The side-effect of XianYu Decoction was less.It could stabilize the tumor , alleviate the symptoms of the medium or late NSCLC patients, improve the quality of life, increase the body weight, improve the immunity. Combined with chemotherapy, XianYu Decoction could enhance the efficacy and reduce the side-effect of chemotherapy.