Pan bread using wheat flour is one of primary staple foods; however, Indonesia imports wheat in large amount. Local crops utilized as flour stocks e.g. porang (Amorphophallus muelleri B.) may reduce imported wheat dependency. Nevertheless, due to porang-flour low solubility and swelling power, modification is needed. The research objectives were to determine effect of heat-moisture treatment (HMT) temperature and time on swelling power, solubility, and lightness of porang flour, to select best treatment, and to determine effect of substitution ratios on physicochemical and organoleptic characteristics of sponge-dough pan bread. Porang flour modification was done with HMT (70, 80, 90°C; 6, 8, 10 h) resulted in increased solubility and swelling power in some cases. Modification at 80°C; 10 hrs exhibited highest swelling power (8.05±0.58g/g); thus, was selected for pan-bread making. Pan bread was prepared with ratios: 95:5, 90:10, 85:15, 80:20, 75:25, 70:30 (wheat flour:modified porang flour). Pan bread (90:10 ratio) exhibited similar volume (887.5±40.59cc) and hardness (824.364±52.30g) to control, and comparable hedonic overall acceptance. Pan bread with partial substitution of wheat flour with modified porang flour, exhibited increased in some proximate compositions but decreased in protein and carbohydrate. Pan bread with 10% substitution could be a future alternative in pan-bread production.