Abstract: The effects of different concentrations of mixed saline-aslkali on seeds and seedlings of Tagetes patula were studied in order to provide theoretical basis for the planting,introduction and domestication of Tagetes patula in salt lake area.By simulating the environmental characteristics around salt lake in Yuncheng city,Shanxi Province,two kinds of neutral salts of NaCl and Na₂SO₄,two kinds of alkali of NaHCO₃ and Na₂CO₃ were selected and mixed according to 1:9:9:1 mole ratio.The concentrations of mixed saline-alkali that NaCl,Na₂SO₄,NaHCO₃ and Na₂CO₃ were set to25,50,75,100,125,150,200 mmol·L^-1 and 300 mmol·L^-1 solution.The results showed that the germination rate,germination energy,germination index and activity index of Tagetes patula gradually decreased;the area of embryo root,germ,hypocotyl and cotyledons decreased;chlorophyll content and relative conductivity of seedlings showed an rising trend;the content of MDA,the activities of SOD and CAT increased and then decreased;the content of free proline（Pro）gradually increased with the increase of the concentration of mixed saline-alkali treatment solution.The greater the concentration of mixed saline-alkali,the more the influences on the seeds and seedlings of Tagetes patula.