This study was undertaken to indentify the key protein (s) which bring about the gel properties of kamaboko and other cooked gel products made from muscular proteins. Mixtures of rabbit actin and myosin of various ratios were prepared. To each mixture was added 2.5% NaCL and cooked in three differet ways: Method I, cooked at 85°C for 30min; Method II, held at 30°C for 30min and cookde as I; Method III, held at 4°C for 24h and cooded as I. Gels optained were submitted to the jelly strength measurement and the differential scanning calorimetry (DSC). The jelly strength values of the gels cooked by Method I increased with increasing myosin content. This indicated that myosin is the essential factor for high jelly strength. Effects of setting treatments of Method III in enhancing the jelly strength were more evidently manifested in the gels with higher myosin content. No effect was found with Method II. The R105 values of DSC which represent the water holding capacity of the gels paralleled the above jelly trength values, indicating that the highly hydrative property of myosin is an essential factor for the high jelly strength. Co-presence of actin and myosin was found essential to bestowing the precooking material with pastiness and consistency with pastiness and consistency which enable the precooking handling like molding or shape giving.