To allow stable treatment, independently of the variation of a treatment amount and prevent the deterioration of photographing performance by containing dextran in treatment liquid.

Dextran is contained in treatment liquid. The average molecule amount of the dextran is preferably 20,000 or less and the content of the dextran is preferably 0.1-100g/l. The treatment can be colored developer which contains p-phenylene diamine based main colored developing chemical with water-soluble groups, bleaching fixer which contains aminopolycarboxylic acid second iron complex salt or stabilizing agent. The dextran is α-1,6 combined D-glucose polymer which is formed by lowering native dextran obtained by the operation of dextran producing bacteria under the existance of sugars to a desired molecule amount with partial decomposition polymerization using acid, alkali and enzyme.