Urban　air　contains　various　kinds　of　organic　pollutants.　Among　them,　several　polycyclic　aromatic　hydrocarbons　(PAHs)　and　nitropolycyclic　aromatic　hydrocarbons　(NPAHs)　are　carcinogenic　and/or　endocrine　disrupting.　PAHs　and　NPAHs　in　the　atmosphere　mainly　originate　from　imperfect　combustion　of　organic　matter,　such　as　petroleum　and　coal.　In　this　study,　total　suspended　particles　(TSP)　were　collected　in　three　different　particulate　size　fractions　by　using　Andersen　low-volume　air　samplers　in　Shenyang,　Shanghai　and　Fuzhou,　China,　in　the　winter　and　summer　seasons　in　2010.　Nine　PAHs　and　twelve　NPAHs　in　the　extracts　from　the　TSP　were　analyzed　by　HPLC　with　fluorescence　detection　and　chemiluminescence　detection,　respectively.　The　mean　concentrations　of　the　sums　of　the　nine　PAHs　and　twelve　NPAHs　were　highest　in　Shenyang　and　lowest　in　Fuzhou.　In　each　city,　more　than　80　%　of　the　total　PAHs　and　total　NPAHs　were　found　in　the　fine　particulate　fraction　(＜　2.1　mu　m).　All　PAHs　and　NPAHs　were　clearly　higher　in　the　winter　than　in　the　summer.　Furthermore,　the　ratio　of　the　molar　concentrations　of　1-nitropyrene　to　pyrene　([1-NP]/[Pyr]),　which　is　a　suitable　indicator　to　estimate　the　contribution　of　diesel-engine　vehicles　and　coal　combustion　to　urban　TSP,　were　smaller　in　Shenyang　in　the　winter.　However,　in　Shanghai,　Fuzhou　and　Shenyang　(summer),　the　[1-NP]/[Pyr]　ratios　were　close　to　those　of　particulates　released　from　diesel-engine　automobiles.　Our　study　showed　that　the　major　contributors　of　atmospheric　PAHs　and　NPAHs　were　diesel-engine　vehicles　both　in　the　winter　and　the　summer　in　Shanghai　and　Fuzhou,　and　in　the　summer　in　Shenyang.　However,　in　the　winter　in　Shenyang,　atmospheric　PAHs　and　NPAHs　seemed　to　be　affected　by　the　mixture　of　coal　combustion　systems,　such　as　coal　heating　and　diesel-engine　vehicles.