Porang is a plant that contains quite high glucomannan. In 2021 the export value of porang has increased by 160% from 2019. The increase in demand for porang is still not supported by the availability of porang tubers so porang exports cannot be maximized. Efforts to meet the availability of porang tubers are to maximize the technical cultivation factory with the availability of quality seeds. This study aims to determine the interaction of bulbil weight and auxin, obtain the best combination of auxin and bulbil weight, as well as the effect of knowing auxin, and the effect of bulbil weight on increasing the growth of porang seedlings. The research was carried out experimentally in the form of a 3 x 4 factorial, arranged using a completely randomized design. Factor I, bulbil weight (5 – 11, >11 – 17, and >17 – 23 g per bulbil). Factor II, auxin concentration (0, 150, 300, and 450 mg.l-1). From these two factors, 12 combinations were obtained, and each combination was repeated 3 times to obtain 36 experimental units. Each experimental unit contained 3 plants in 3 polybags so a total of 108 plants were observed. Parameters observed were the days of shoot emergence, height, stem diameter, root volume, and fresh seedling weight. The results showed that the combination of bulbil weight >17 – 23 g and an auxin concentration of 300 mg.l-1 gave the best results for the growth of porang seedlings on all observation parameters. Bulbil weight > 17 – 23 g markedly increased seedling growth in all observation parameters, and administration of auxin concentration of 300 mg/l-1 also significantly increased porang seedling growth in all observed parameters.