In order to study mutagenic effects of different heavy ions irradiation on maize inbred lines, corn seeds of Zheng58, Lu9801, Jinxiang4C-1, CSR24001, 308 and 478 were irradiated with ,12,C,6+, and ,36,Ar,18+, ions. The experimental results showed that the germination rate and planting percent were different after irradiation. The wettish seeds had higher sensibility to heavy ion irradiation. The leaf type of the plant appeared visible changes in M,1 ,generation. In M,2, generation, great changes had taken place in economic traits, many of which are beneficial mutation. Some beneficia1 mutation could be stably inherited in M,3, generation. From the above, it can be predicted that heavy ions irradiation is an effective means of genetic improvement of maize.