Objective：To observe the effects of phthalate acid esters （PAEs） on the gene expression of peroxisome prolifcrator activat－ed receptor gamma2 （PPAR-γ2） in primary rat adipocytes. Methods：Adipocytes in cultures were exposed to PAEs. Main experi－ments：①observed morphological changes of adipocytes by microscope every day；②Oil red O staining and MTT assay method were used to check the growth status of adipocytes；③Total RNA from these adipocytes was extracted by reverse transcription PCR. Results：①Morphological of adipocytes with PAEs changed from Small round to spindle and finally turned into oval. lipochondrion was observed in adipocytes. Along with the increase of culturing time，lipochondrion in adipocytes gradually increase，finally part of lipochondrion fusion to a bigger lipochondrion，accord with the developing law of adipocytes.②A large lipochondrion was present as medium of concentration of PAEs increased；③The expression of PPAR-γ2 increased as concentration of PAEs increased. The results of this study will provide the scientific basis for the relationship with obesity，and provide a new idea for the the further research of the effects of PAEs to health. Conclusion：The major role of adipocytes growth perhaps is that PAEs enhanced the expression of PPAR-γ 2.