The　internal　exposures　to　polycyclic　aromatic　hydrocarbons　(PAHs)　of　pregnant　women　from　Shanghai　were　assessed　through　the　detection　of　urinary　PAHs　metabolites.　Several　monohydroxylated　PAHs　(OH-PAHs)　were　monitored,　and　the　mean　concentrations　of　2-Hydroxynaphthatene　(2-OHNap),　2-Hydroxyfluorene　(2-OHFlu)　and　1-Hydroxypyrene　(1-OHPyr)　were　0.57　mu　g/mmol　creatinine,　0.32　mu　g/mmol　creatinine　and　0.06　mu　g/mmol　creatinine,　respectively.　Relative　high　concentrations,　especial　2-OHFlu,　can　be　found　in　Shanghai　compared　with　previous　studies.　The　profile　of　different　OH-PAHs　was　calculated　and　2-OHNap　was　the　main　component.　The　concentration　of　1-OHPyr　is　almost　one　order　of　magnitude　lower　than　that　of　2-OHNap.　All　the　correlation　studies　indicate　that　monitoring　of　2-OHNap,　2-OHFlu　and　1-OHPyr　as　multiple　biomarkers　are　more　suitable　than　1-OHPyr.　Smoking　can　obviously　affect　the　concentration　level　of　2-OHNap　in　urine　samples,　but　no　significant　difference　is　observed　between　levels　of　2-OHFlu　and　1-OHPyr　in　smokers　and　nonsmokers.　The　concentration　of　2-OHNap　seems　to　be　more　sensitive　to　cigarette　smoke　than　other　analytes.