The catalytic activities of potassium dihydrogen phosphate for nitrations of toluene were studied． Effects of catalyst dosage，reaction condition and recovered catalyst on the regioselectivities of toluene were investigated． The result shows high regioselectivity when 0.6 g potassium dihydrogen phosphate catalyst is used with 95% nitric acid as nitrating reagent in the presence of acetic anhydride,in 60 min at 55 ℃. The ortho-paro isomer ratio is 0.96,lower than 1.67 with sulfonitric acid as catalyst. The yield of product is 95.1%. The catalyst is reutilized up to five times with little change in activity.