Objectives: To study change of plasma concentrations of CYFRA 21-1, CEA and SCC among NSCLC patients at Nuclear Medicine and Oncology Center of Bach Mai Hospital. Methods: A prospective study was conducted on 45 NSCLC patients with IIIB and IV stage had been done with three tests as CYFRA 21-1, CEA, SCC at pre-treatment and post treated by PC therapy from Mar to Oct. 2014 at Nuclear Medicine and Oncology Center of Bach Mai Hospital. Results: Plasma CYFRA 21-1 concentration of patient with bronchial adenocarcinoma (before: 19.43 +/- 16.85 ng/ml, after: 10.96 +/- 13.30 ng/ml) and squamous cell carcinoma (before: 30.45 +/- 14.53 ng/ml, after: 18.82 +/- 10.73 ng/ml, respectively) and IIIB stage (before: 12.08 +/- 9.84 ng/ml, after: 5.20 +/- 5.61 ng/ml) and IV stage (before: 27.59 +/- 17.81 ng/ml, after: 17.13 +/- 14.55 ng/ml).CEA concentration of patient with bronchial adenocarcinoma (before: 249.42 +/- 332.36 ng/ml, after: 170.23 +/- 239.79 ng/ml) and squamous cell carcinoma (before: 8.02 +/- 6.71 ng/ml, after: 4.53 +/- 3.13 ng/ml) and IIIB stage (before: 48.97 +/- 114.51 ng/ml, after: 36.04 +/- 101.75 ng/ml) and IV stage (before: 311.52 +/- 361.24 ng/ml, after: 210.60 +/- 259.11 ng/ml). Conclusions: all of CYFRA 21-1, CEA, SCC concentrations reduce among squamous cell carcinoma group and bronchial adenocarcinoma group and IIIB stage and IV stage. No patient must stop the treatment.