Demand of cocoa products continues to increase, however there was a decrease in the production of cocoa which resulted in increasing price of cocoa. Previous researches had utilized fermented jackfruit seed and carob flour as cocoa powder substitute but none has been satisfactory. The utilization of fermented durian seed as cocoa powder substitute can be used to completely substitute cocoa powder in baked brownie production with good acceptance, however the color was significantly lighter. In this research, different fermentation medium and alkalization process were employed with aims to improve the sensory characteristic of the durian seed powder. The fermentation was carried out at room temperature for 7 days in an anaerobic condition with different ratio of ripe durian pulp and okara (1:0, 1:1, and 0:1) as the fermentation medium added with 3% S. cerevisiae. The alkalization process were done by using either NaOH or K2CO3 with a concentration of 3% or without alkalization. All the alkalized and non-alkalized fermented durian seed were dried in the same condition, roasted at 180ºC for 40 minutes, grinded, and sieved pass 200 mesh. Based on the research, the best fermentation medium was 100% ripe durian pulp and alkalization process can improve the aroma and color of fermented durian seed powder especially with NaOH as the alkali solution. The alkalized fermented durian seed that was fermented using 100% ripe durian pulp and had undergone alkalization process with 3% NaOH had a chocolate aroma that was not significantly different with the Classic and Dark commercial cocoa powder with Chroma value of 20.07±0.38 and °Hue of 67.72±0.45 which fall into the color range of yellow-red.