To suppress silver stain in a developing tank, etc., without affecting photographic performance and to facilitate easy maintenance of a processing machine when a rapidly processable photographic sensitive material is processed by incorporating a developing agent and plural kinds of specified compds.

This developing soln. contains a developing agent, at least one of compds. represented by formulae I-V and at least one kind of compd. represented by formula VI. In the formulae I-V, each substituent R is H, a halogen, a substituent bonding to a ring through C, O, N or S, at least one R in each of the formulae is mercapto and two kinds of radicals each obtd. by releasing one arbitrary H atom on C forming a 6-membered ring may bond to each other to form a bis type structure. In the formula VI, each of R61-R64 is H, an alkyl, an aryl, etc., at least one of them is mercapto, at least one of them is OH and R62 and R63 may bond to each other to form a cyclic structure.