Commercial mayonnaise currently available is full fat mayonnaise with high oil content (70-80%) which can be harmful to health when consumed in the long time. Reduced fat mayonnaise (RFM) as an alternative mayonnaise, which reduces the oil content causes the emulsion changes so a stabilizer is needed. The stabilizer that can be used is porang flour which rich in glucomannan. This study aimed to determine the physicochemical and sensory of RFM with variations in oil (M) (40%, 50%, and 60%) and porang flour concentration (P) (0.1%, 0.2%, and 0.3%). This study used a Completely Randomized Design. Physicochemical parameters include water content, ash content, fat content, protein content, pH, viscosity, emulsion stability, color and emulsion droplets. The result showed that RFM has water content content 26,14 - 44,25%, ash content 0,52% - 0,60%, fat content 37,61% - 64,11%, protein content 3,35% - 3,76%, pH 4,07 - 4,17, viscosity 639,90 cP - 9250,00 cP, emulsion stability 99,98% - 100%, and color L* 83,92 - 85,72, a* 2,67 - 5,92, b* 20,28 - 29,25, and chroma 20,75 - 29,48. M2P3 was the selected formulation with higher acceptance for parameters such as color, aroma, texture, taste, and overall compared to the control mayonnaise.