Abstract: Changes of related enzymes and antioxidant activities in the process of amaranth growth were explored.The amaranth seeds were treated with various concentrations of MeJA and the optimal concentration was determined according to the growth of amaranth bud and the content of amaranthin. During the cultivation of amaranth bud treated with optimal concentration, the germination rate, germination energy, germination index, vigor index were investgated. Then the amaranth bud were collected regularly ( 2, 4, 6 and 8 d) for the determination of root length, overall length, amaranth content, total phenolic contents, hydrogen peroxide ( H₂ O₂) content and antioxidant enzyme activities.The results showed that 100 μmol/L MeJA treatment was not good for seed germination, which inhibited the root length and overall length significantly.However, it enhanced the contents of amaranth and total phenolic when compared to the control group.It eliminated O₂^-·by improving the activity of SOD, and it could also reduce the H₂ O₂ accumulation in amaranth bud by delaying the increase of POD activity and the decrease of CAT and APX activities.This study would provide a new method to increase the yield of natural amaranthin, and it also provides theoretical basis for the further study of changes of related enzymes and antioxidant activities in the process of amaranth growth.