A series of strontium substituted perovskite-type catalysts La(1-x)SrxTiO3(x=0~0.6)for diesel soot combustion were prepared by citric acid complexometry method.These catalysts were characterized by X-ray diffraction,BET,SEM and so on.Their catalytic performances when their A sites were substituted by Sr were investigated by TG-DTG.The results indicate that the catalytic activities of La(1-x)SrxTiO3 for soot combustion increased first and then decreased with increasing strontium substitution amount.The optimum substitution amount of strontium was 0.3 among these catalysts.The catalyst La0.7Sr0.3TiO3 possessed integrated perovskite-type structure after 800 ℃ calcination and its optimum catalytic activity was ti=338 ℃,tm=422 ℃.However,the catalytic activities of these catalysts did not increase further with increasing Sr when Sr-substitution amount was greater than 0.3.The reason is that TiO2 phase appeared in the perovskite-type structure when x>0.3,which destroyed the perovskite crystal form and inhibited the catalytic properties of the catalyst.