Abstract: Objective 　To investigate the influence of ¹⁸⁸ Re-DTPA-DG on human pulmonary carcinoma cell line and elucidate its possible mechanism. Methods 　A549 cells were cultured, they were divided into 3groups, namely, ¹⁸⁸ Re-DTPA-DG,control, saline group, and the former two groups were divided into 3 groups respectively by 3 different concent rations (148 、296 、444MBq/ L), then they were acted on respectively through a night . Cell growth was assessed with MTT before the appearance of the cells was watched with microscope. Results 　The ability of growth was inhibited in about 16 hours, and the inhibiting ratio was higher in ¹⁸⁸ Re-DTPA-DG group than in cont rol group ( P < 0. 001) . In ¹⁸⁸ Re-DTPA-DG group, when there is a higher concent ration, the inhibiting ratio also becomes higher ;while in ¹⁸⁸ ReO -₄ group, it does not . Conclusion 　The influence of ¹⁸⁸ Re-DTPA-D Gis superior to ¹⁸⁸ ReO -₄ on human pulmonary carcinoma cells, which may cont ribute to the mechanism that ¹⁸⁸ Re-DTPA-DG can be involved in tumor cells while ¹⁸⁸ ReO -₄ can not, and the cell injury extent occurred by them is different .