The aim of this study was to assess the suitable hormonal balance on potato microtuberization from the plantlets which had been in heat therapy condition before culturing the meristem. The effects of different levels of BAP and sucrose concentration were studied 16 weeks after the last culture in two genotypes. Explants from meristem were propagated in vitro in several stages and then subcultured with MS medium containing the combination of BAP (three levels) and sucrose (three levels). Then they were transferred to a completely dark incubation room at 22 °C. In vitro tuber formation was analyzed 16 weeks later. Traits which studied were: length, diameter, fresh weight and number of micro tubers. There was no significant difference among the genotypes for all the traits. The micro tuber number was significantly different among the levels of BAP concentration and the BAP and sucrose interaction was significant for the diameter. The micro tuber fresh weight and diameter were highly significant for the sucrose levels. The sucrose and genotype interaction for micro tuber length; sucrose and BAP interaction for micro tuber length and diameter were significant. Also the genotype, BAP and sucrose interaction was significant for the micro tuber fresh weight.