The effect of freshwater crab meat additive on protein quality of tofu was studied. Tofu containing freshwater crab meat(TCM) prepared by the formulation for the best sensory qualities had about 20% more lipid and ash content than those of commercial tofu. TCM showed a higher content of lysine, methionine, cysteine and tyrosine compared with those in commercial tofu. TCM was comparable to commercial tofu(CT) regarding the in vitro protein digestibility(95%). A considerable difference in computed protein efficiency ratio(C-PER) resulted between CT(1.76-1.81) and TCM(2.61). Therefore, crab meat has potential as an ingredient for enriching essential amino acid and improving protein quality of CT.