1) A developer containing 0.05 M-Ti³⁺-EDTA for the treatment of a negative film was investigated. To prepare this solution, 0.05 mol TiCl₃ and 0.075 mol EDTA·2Na·2H₂O are mixed per 1, 000 ml. Acetic acid and Na acetate are added to adjust pH 3.15. The color of the Ti³⁺-EDTA developer is violet, while the oxidized solution turns non-colored. The photographic qualities of the negative processed with the Ti³⁺-EDTA developer are a little inferior to D-76. 2) Although the redox potential of the Ti³⁺-EDTA solution is nobler than the non-chelated Ti³⁺ solution, the developing action of Ti³⁺-EDTA solution is more vigorous than that of the non-chelated Ti³⁺ solution. On the other hand, the potential of Fe²⁺-EDTA solution is less noble than the Fe²⁺ solution not etiolated, and the developing action of Fe²⁺-EDTA is stronger than that of Fe²⁺. 3) Ti3+-EDTA developer made by the method of electrolytic reduction of Ti⁴⁺-EDTA solution can maintain its developing power repeating the development of films and the electrolytic reduction.