In a new vanadium production process, the effective separation of Na3VO4 and Na2CrO4 from the NaOH-NaNO3-Na3VO4-Na2CrO4-H2O system plays a very important role. In this regard, the dissolution behavior of Na3VO4 and Na2CrO4 in the NaOH-NaNO3-Na3VO4-Na2CrO4-H2O system was investigated by measuring solubility data, and finally the solubility diagram was constructed. From the data, a method of separating Na3VO4 via cooling crystallization and Na2CrO4 via evaporization in the concentrated alkaline solution is proposed.