The catalyst of rare earth(Ⅲ) perfluorooctanesulfonates(RE(OPf)₃, RE=La, Sm, Eu, Tb, Yb, Lu) were prepared for the nitration of toluene in fluorous biphasic system. Perfluorohexane (C₆F₁₄), perfluoro- methylcyclohexane (C₇F₁₄), perfluorotoluene (C₇F₈), perfluorooctane (C₈F₁₈), perfluorooctyl bromide (C₈F₁₇Br) or perfluorodecalin (C₁₀F₁₈, cis and trans-mixture) were used as fluorous solvent respectively for this reaction. Effects of rare earth metal salts with different ligands and amount of the catalyst on the reaction were studied. The results show that Yb(OPf)₃ and C₁₀F₁₈ are the best catalyst and fluorous solvent respectively. The yield of nitration of toluene is 56% by using Yb(OPf)₃ as a catalyst and C₁₀F₁₈ as a fluorous solvent, and para-selectivity is 45%; By simple separation of the fluorous phase containing only catalyst, nitration can be repeated many times.