PURPOSE: To provide a method for development by which blackness of silver in a picture image is improved without desensitization in the rapid treatment of a high sensitive emulsion using a highly active developer.

CONSTITUTION: This method features in treating a silver halide photographic sensitive material with a developer containing a nitrogen-contg. heterocyclic mercapt compd. and a compd. expressed by formula. In formula I, R is an aryl group, R1, R2, R3, and R4 may be same or different, hydrogen atoms, alkyl groups, aryl groups, or aralkyl groups. However, if R is a unsubstd. phenyl group, all of R1, R2, R3, R4 are not hydrogen at one time.