Abstract: In order to provide a quickly quantitative analysis of transferring of colored valence ions in chemical reactions, electrolytic conversion of titanium ion in electroless nickel bath was investigated in this paper. Ti³⁺ lost its reducibility when it was oxidized into Ti⁴⁺ in process of electroless nickel plating with TiCl₃ as a reductant.Electrolysis was introduced as a regeneration method of electroless nickel bath. Concentrations and relevant transferring rate of titanium ion were quantitatively analyzed with aids of spectrophotometry. In addition to RGB values of bath images, equation of chromaticity relative value and Ti³⁺ content was investigated based on colorimetric quantification of electrolysis bath. Results show that Ti⁴⁺ can be transferred to Ti³⁺ with its transferring rate η up to 94.16% by electrolysis regeneration process. Furthermore, ion reduction procedure can be evaluated by image colorimetry. Chromaticity relative value U of the bath and Ti³⁺ concentrations exhibits good liner correlation chromaticity relative value U of the bath and Ti³⁺ concentrations exhibited good liner correlation with the coefficient R as 0.976 03.