There is provided a method of producing a rare earth salt of a dialkyl phosphate or a rare earth salt of dioleyl phosphate of a high purity useful as a polymerization catalyst of a conjugated diene compound by directly reacting a rare earth oxide or a rare earth hydroxide with a dialkyl phosphate or dioleyl phosphate of a high purity. In the invention, the rare earth oxide or rare earth hydroxide is reacted with the dialkyl phosphate or dioleyl phosphate of a high purity in a non-polar solvent in the presence of at least one compound selected from a halogenated hydroacid, phosphorous acid and a rare earth halide made from the same element as in an objective product as a catalyst.
                            提供了一种制备高纯度的二烷基
磷酸稀土盐或双油酰基
磷酸稀土盐的方法,该方法可用作共轭二烯化合物的聚合催化剂。该方法直接将高纯度的二烷基
磷酸盐或双油酰基
磷酸盐与稀土氧化物或稀土氢氧化物在非极性溶剂中反应,同时在催化剂的存在下加入至少一种从卤化羟酸、
磷酸和与目标产品中相同元素制成的稀土卤化物。