We measured the normal-state Hall effect on the polycrystal of YBa₂(Cu_1-xM_x)₃O_y (M=Fe, Co) prepared by two kinds of heat treatments. The synthesized YBa₂ (Cu_1-xM_x)₃O_y (M=Fe, Co) was slowly cooled from 890°C in air. Some of them were annealed below 400°C in O₂ gas (sample [O]s). The others were heated at 800°C in N₂ gas followed by annealing below 400°C in O₂ gas (sample [NO]_s). It is considered that there is a difference in the configuration of substituent in the Cul-0 planes between [O]_s and [NO]_s: in [O]_s the substituent is randomly located, while in [NO]_s that makes clusters. The carrier density nH of [O]_s and [NO]_s in YBa₂(Cu_1-xCo_x)₃O_y system decreases with an increase of x. In the case of YBa₂(Cu_1-xFe_x)₃O_y system, nH Of [0]_s decreases with an increase of x, while that of [NO]_s is almost constant independent of x. The difference in the behavior of nH between YBa₂(Cu_1-xFe_x)₃0_y and YBa₂(Cu_1-xCo_x)₃O_y systems seems to be due to the difference of the microscopic structure around the substituent.