Abstract: Objective: To investigate the best choice of combined treatment to human pulmoal giant cell carcinoma cells（PLA-801D）with mixture of NK and T lymphocytes（NKTm cells）and cisplatin（DDP） in different sequences.Methods: The inhibited rates of PLA-801D cells treated by single NKTm cells,single DDP,and combined treatment of NKTm cells and DDP in different sequences were determined with MTT colorimetric assay.Results: The effect of combined treatment of NKTm cells and DDP excelled the effect of single NKTm cells treatment and single DDP treatment（P＜0.01）.Values of Q in all the combined group were more than 1.15;among all the group,the sequence of using NKTm cells first,and then 4 h later using DDP had the highest Q value（Q=2.297）.Conclusion: Combined treatment of NKTm cells and DDP had synergistic effect to inhibit PLA-801D cells.The best sequence was to using NKTm cells first,and then 4 h later using DDP.