An aqueous solution containing an organic acid chromium (III) salt represented by general formula: Crm(Ax)n, wherein A represents a residue left after proton removal from an organic acid; x represents a charge of A; and m and n represent integers satisfying equation 3m+xn=0, is disclosed. The aqueous solution contains the organic acid chromium (III) salt in a concentration of 6% by weight or higher in terms of Crm(Ax)n, has impurity ion concentrations of Na≦30 ppm, Fe≦20 ppm, Cl≦0.001%, SO4≦0.03%, and NO3≦20 ppm per 20 wt % concentration of Crm(Ax)n, and is substantially free from chromium (VI).