The gas-phase reactions between thiophene and active radicals are of great importance in the combustion chemistry and atmosphere chemistry.In this study,the dynamics of the reaction of thiophene with hydroxyl radical is theoretical investigated at QCISD(T)/6-311+G(d,p)//MPW1PW91/6-311+G(d,p).The results shows that four distinction reaction path exist for the title reaction: hydrogen abstraction(R1 and R2),substitution of H atoms by OH radical(R3 and R4),addition of OH radical to S atom cause H elimination(R5),and addition of OH radical to thiophene cause ring-opening(R6 and R7).the energy barriers of the reactions R1,R2,R3,R4,R5,R6 and R7 are 31.64,36.84,159.63,116.89,329.47,103.39 and 73.89 kJ mol-1,respectively.Thus the hydrogen abstraction is the dominant reaction.