Abstract: Objective 　To evaluate the efficacy and toxicity of paclitaxel combined with cisplatin in the t reatment of advanced non2small cell lung cancer (NSCLC) by double and three2week regime. Methods 　Sixty patient s with locally advanced ( stage Ⅲ) or metastatic ( stage Ⅳ) NSCLC were enrolled into the study and divided to two group s. Double week regime ( n = 30) : paclitaxel 80 mg/ m2, cisplatin 40 mg/ m2 ivgtt d1, 8, and it was repeated at d 21. Three2week regime ( n = 30) : paclitaxel 140 mg/ m2, cisplatin 60 mg/ m2 ivgtt d1 and it was repeated at d 21. A HPLC method was established for the determination of pa2 clitaxel at 3, 12, 24 h af ter administ ration, and evaluate the efficacy and toxicity af ter two chemotherapy cycles. Results 　The overall response rate of double week regime and three2week regime were 40. 0 % and 36. 7 %, respectively, there was no statistic difference, but the main toxicities of double week regime were lower. Conclusion 　Double week regime is a better method for the t reatment of advanced NSCLC, it could increase patient s for further study.