Mud clam (Polymesoda erosa) hydrolysate (AH) was produced by hydrolysis for 2 hrs using alcalase 2.4L at pH 8.5, 60°C and 3% enzyme-substrate ratio. D-xylose and L-cysteine or D-xylose were added into the hydrolysate and heated at 120°C for 2 hrs to produce the Maillard reaction products (MRPs) labelled as AH-mx or AH-x, respectively. Amino acids, volatile compounds and sensory characteristics of AH and MRPs were evaluated. Amino acids analysis showed that monosodium glutamate (MSG)-like amino acids amount was higher while 2-piperidinone volatile compound that contributes to bitterness was lower in MRPs than AH. Furthermore, sensory results showed that MRPs had more intense umami and less fishy taste compared to AH. Therefore, it was discovered that Maillard reaction improved the flavor of mud clam hydrolysate.