Phthalates　are　widely　used　in　industry　as　solvents,　additives　and　plasticizers.　Some　phthalates　and　their　monoester　metabolites　are　known　to　cause　carcinogenic,　toxic　or　endocrine-　modulating　effects.　Chorion　tissues　as　human　early　embryo　are　the　base　of　organogenesis.　Embryo　(3-　8　weeks)　is　sensitive　period　of　teratogensis.　With　the　development　of　industrialization,　in　addition　to　genetic　factors,　environmental　factors　become　an　important　reason　for　human　reproductive　system　defect,　particularly　under　the　interaction　of　the　environmental　factors　and　genetic　factors.　Recently　we　have　studied　human　chorion　tissues　to　see　whether　the　phthalates　especially　their　monoester　metabolites　are　exist　in.　In　the　result　five　phthalates　and　monoester　metabolites　such　as　dibutyl　phthalate　(DBP),　butyl　benzyl　phthalate　(BBP),　di(2-　ethylhexyl)　phthalate　(DEHP),　monobutyl　phthalate(MBP)　and　mono(2-　ethyl-　hexyl)　phthalate(MEHP)　are　discovered,　that　means　that　phthalates　and　their　monoesters　both　can　pass　through　embryo　and　affect　fetus　before　birth.