Abstract: Taking the seeds of the yellow marigold cultivar in the ‘Antigua’ series as the test material, the petri dish germination method and plug seedling method were carried out, the seeds and seedlings were subjected to salt stress at different concentrations(0（CK）,50,100,200,400 mg·L^-1) GA₃ treatment, samples were collected regularly, germination indicators, seedling agronomic traits, stress resistance physiological and biochemical indicators were observed, the effect of exogenous GA₃ on Tagetes erecta L.seeds under salt stress effects of germination and seedling growth was studied, in order to screen the optimal GA₃ concentration for mitigating salt damage to Tagetes erecta L.seeds and seedlings.The results showed that the germination of Tagetes erecta L.seeds and the growth of seedlings were inhibited by salt stress, and the value of each treatment index was significantly lower than that of the control; with the increase of GA₃ concentration, the germination rate, germ length, radicle length, seedling height, root length, the indexes such as chlorophyll content, peroxidase and superoxide dismutase activities generally showed a trend of first increasing and then decreasing; salt damage index and malondialdehyde content showed a trend of first decreasing and then increasing.The application of medium and low concentrations of exogenous GA₃ can significantly reduce the damage to Tagetes erecta L.seeds and seedlings under salt stress, and the concentration of 100 mg·L^-1 GA₃ could best alleviate the inhibitory effect of salt stress on its growth.An appropriate concentration of exogenous GA₃ can enhance the salt tolerance of Tagetes erecta L.seeds and seedlings and promote their growth.