Effects of exogenous abscisic acid (ABA) on the growth and some physio-biochemical signs in wheat (Triticum aestivum L.) seedlings under cadmium stress (100 mg/L) were studied with hydroponics.The results showed that:(1)The malondialdehyde (MDA) content in wheat seedlings was significantly increased (P<0.05),and the growth of wheat seedlings was also obviously inhibited by Cd²⁺ stress.(2)Exogenous ABA with the concentration of 5.0 μmol/L playing a noticeable role increased root activity and proline content,enhanced activities of SOD,POD and CAT,and decreased MDA content.(3)Exogenous 1.0~5.0 μmol/L ABA eased the negative effects of Cd²⁺ on the growth of wheat seedlings,and 5.0 μmol/L ABA worked best with shoot height,root length and total biomass of seedlings in 5.0 μmol/L ABA and Cd²⁺ stress had increased 6.73%,149% and 10.52%,respectively,compared with those under single Cd²⁺ stress.However,10.0 μmol/L ABA exacerbated the growth of wheat seedlings.On the whole,preference concentration of exogenous ABA could ease the inhibitory effects of Cd²⁺ stress on the growth of wheat seedlings and boost the tolerance of wheat seedlings to Cd²⁺ stress by increasing SOD,POD and CAT activities and proline content.Furthermore,the most suitable concentration of ABA was defined to be 5.0 μmol/L.