Abstract: Flowering time directly controls the length of nutritional and reproductive stages of plants,determines whether plants can reproduce successfully or not,and closely associates with the plant yield and quality properties depended by human beings. Mutants of Arabidopsis thaliana are widely used important genetic materials for the study in flower time regulation.In our previous studies,an Arabidopsis thaliana late flowering mutant line pex2-gt+ was obtained. Based on this mutant, Southern blot and Tail-PCR experiments were carried out and the results showed that the late flowering phenotype was caused by the T-DNA insertion in pex2 site.This study can contribute to the further study of the biological function of pex2.