Abstract ：Transformation effection of GUS gene introduced into Arabidopsis seeds mediated by ion beam was studied. The result was that transient expression had no obtained after transformating dry seeds implanted.But if 2d-seedles was implanted, and then dip into DNA solution, the transformation effect was increases evidently. 10% transient expression was obtainted. The results tell us small seeds such as arabidopsis seeds maybe obtain better transformation effect when 2d-seedles were implanted firstly and then dip into DNA solution.