PURPOSE: To produce a dispersion useful as a silver halide photographic material, having high brightness and sensitivity and hardly causing the fog by mechanically dispersing a specific organic dye in the presence of a polar organic solvent in an aqueous medium.

CONSTITUTION: An organic dye of the formula [R3 and R4 are each an alkyl, an alkenyl, an aryl, etc.; X is CN, COOR5, SO2NR5R6 (R5 and R6 are each H, an alkyl, an alkynyl, etc.), etc.; L1 to L3 are each methine; (n) is 0-2] is mechanically disperded in the presence of a polar organic solvent in an aqueous medium with a high-speed impeller dispersing machine and the resultant dispersion is then heated to ≥50°C, preferably under pressure. Thereby, a part of the organic solvent is removed.