A　method　for　the　determination　of　phthalate　monoesters　and　diesters　in　urine　by　solid-phase　extraction　and　gas　chromatography-mass　spectrometry　(SPE-GC-MS)　was　developed.　After　urine　enzymatic　hydrolysis　by　β-glucuronidase,　the　sample　was　pretreated　by　SPE.　Phthalate　monoesters　and　diesters　were　eluted　by　acetonitrile,　ethyl　acetate　and　ethyl　ester-n-hexane　(1:　19,　v/v),　separately.　The　mixture　of　the　elution　was　dried　by　N2　and　derivatized　with　N,O-bis(trimethylsilyl)trifluoroacetamide　before　GC-MS　analysis.　Good　linear　relationships　were　obtained　in　the　range　of　5-1000　μ　g/L.　The　limits　of　detection　were　between　0.3　and　1.1　μ　g/L.　The　recoveries　of　phthalate　monoesters　and　diesters　were　in　the　range　of　77.9%-97.7%　and　the　relative　standard　deviations　(RSDs)　were　3.7%-10.9%.　The　method　was　applied　to　analyze　50　urine　samples.　Seven　compounds,　such　as　di-2-ethylhexyl　phthalate　(DEHP),　were　detected.　The　mean　concentrations　were　between　6.0　and　142.7　μ　g/L.　The　method　is　highly　accurate,　reliable　and　sensitive　for　monitoring　phthalate　monoesters　and　diesters　in　urine.