Water-holding capacity (WHC) of heat-induced pork gels was examined. The heat-induced gels were obtained from meat homogenates prepared by adding nine volumes of 0.3-0.5mol/L NaCl solutions containing 9-36mmol/L disodium inosine-5-monophosphate (IMP) or 9mmol/L tetrapotassium pyrophosphate (KPP) to minced pork. IMP at 36mmol/L enhanced the WHC to the same level as attained by KPP. Physical and sensory properties of heat-induced gels were also examined. The heat-induced gels were prepared from porcine meat homogenates containing 0.3mol/L NaCl and 9-36mmol/L IMP or 9mmol/L KPP. IMP at 36mmol/L enhanced the values of hardness, cohesiveness, gumminess and springiness, measured with a Tensipresser, and several organoleptic scores to the same level as the score attained by KPP. Thus, it is concluded that IMP is expected to be a practical substitute for pyrophosphates to improve the quality of sausages.