Objective:To investigate the association of the transportation characteristics of nolatrexed in tumor cells with its drug sensitivity. Methods: The sensitivity of 3 tumor cell lines, C6, SRS82 and LoVo, to nolatrexed were determined by growth inhibition study. After exposure to 20 μmol/L nolatrexed at different time intervals ranging from 0 to 30 min, or to nolatrexed at different concentrations ranging from 0 to 40μmol/L for 10 min, the intracellular drug concentration was measured using high-performance liquid chromatography. Results: C6 was the most sensitive cell line among the three, with sensitivity 6. 8-fold and 13.8-fold those of SRS-82 and LoVo cells respectively. Transportation of nolatrexed in the 3 cell lines were qualitatively similar, which rapidly achieved steady-state within 5 min, and linear relationship between the intracellular and extracellular drug concentration was observed. The intracellular steady-state level achieved in C6 was significantly higher than those in the other two cell lines, the latter having comparable levels. Conclusion: Nolatrexed enters the cell very quickly and different transport capacities are involved in the generation of varied sensitivity to nolatrexed in tumor cells.