The　low-low　temperature　electrostatic　precipitator　(LLT-ESP)　has　been　applied　in　many　power　plants　to　improve　the　emission　performance.　In　this　study,　a　number　of　fix-bed　experiments　were　conducted,　which　simulated　the　operation　condition　of　LLT-ESP.　The　effect　of　chemical　composition　on　the　adsorption　characteristics　of　ash　samples　and　the　agglomeration　after　adsorption　were　studied.　The　results　show　that　the　agglomeration　of　ash　particles　occurs　in　three　forms,　including　agglomeration　among　small　particles,　adhesion　of　loose　pellets　to　large　particles,　and　agglomeration　among　large　particles.　The　capacity　of　ash　particles　to　adsorb　sulphuric　acid　is　less　affected　by　the　increase　of　added　amounts　of　NaCl　or　KCl.　At　the　same　time,　the　added　amount　of　NaCl　or　KCl　also　has　little　effect　on　the　agglomeration　degree　of　ash　particles.　The　addition　of　MgO,　CaO,　Fe2O3,　Na2CO3,　or　K2CO3　from　0%　to　13.3%,　22.4%,　23.9%,　18.4%,　or　14.2%,　promotes　the　adsorption　of　sulphuric　acid　by　ash　particles　from　1.95　mg　g(-1)　to　7.33,　7.71,　6.72,　5.1,　or　5.44　mg　g(-1)　(based　on　sulphur　content),　respectively,　thereby　promoting　the　agglomeration　between　ash　particles.　As　the　addition　amount　increases,　the　agglomeration　phenomenon　among　particles　becomes　more　conspicuous.　The　form　of　agglomeration　changes　from　agglomeration　among　small　particles　to　agglomeration　among　large　particles.　In　addition,　the　addition　of　MgO　or　CaO　has　great　influence　on　the　adsorption　and　agglomeration.