PM2.5　samples　of　winter　and　summer　were　measured　and　WRF-CAMx　modeling　system　was　developed　to　simulate　PM2.5　and　secondary　inorganic　ions　in　Beijing-Tianjin-Hebei　to　study　pollution　characteristics　and　regional　transmission　of　PM2.5　in　Tangshan,　which　obtained　PM2.5　chemical　components　data　and　estimated　the　regional　contribution　to　PM2.5　and　secondary　inorganic　ions.　Results　indicate　the　concentration　of　PM2.5　are　(117.9±56.6)　μg/m3　and　(77.3±29.8)　μg/m3　and　have　the　standard　exceeding　ratios　of　65.0%　and　41.7%,　total　water-soluble　ions　concentrations　are　(58.4±17.9)　μg/m3　and　(42.6±23.6)　μg/m3,　which　account　for　49.4%　and　55.0%　in　winter　and　summer,　representing　major　chemical　components　of　PM2.5.　Cu,　Zn,　As,　Sr,　Cd,　Sb,　Pb　mainly　come　from　anthropogenic　pollution　sources,　while　the　others　such　as　Na,　Mg　come　from　crustal　sources.　The　contribution　of　non-local　sources　to　PM2.5　was　26.9%　and　31.1%　in　winter　and　summer　respectively.　The　transmission　effect　of　SIA　was　more　significant　compared　to　PM2.5.　The　contribution　of　non-local　sources　to　PM2.5　and　SIA　in　summer　was　higher　than　that　in　winter.　The　contribution　of　non-local　sources　had　a　certain　degree　of　rise　during　the　high　concentration　process.　Stable　atmospheric　conditions,　low　wind　speed　and　increasing　coal　emissions　are　main　causes　of　heavy　pollution　process.　©　2017,　Editorial　Department　of　Journal　of　Beijing　University　of　Technology.　All　right　reserved.