Carp meat has weak gel-forming and slow setting properties. To clarify the factors of such properties seems to be necessary to utilize fish meat like carp for making kamaboko. Meat sols were prepared in various combination with CaCl2, (transglutaminase (TGase) activator), EGTA, (TGase and metallo-endopeptidase inhibitor), and E-64, (cystein-endopeptidase inhibitor). Sols were incubated at 30, 40 and 50°C (first step), then heated at 85°C for 0.5 h (second step). First step sols at 30°C did not set, however, breaking strength of second step gels were improved with CaCl2. At 40°C, CaCl2+E-64 improved breaking strength of gels remarkably and EGTA+E-64 did so slightly. At 50°C, EGTA, CaCl2+E-64 and EGTA+E-64 improved breaking strength of gels greatly. E-64 inhibited degradation of myosin heavy chain (HC) at 40 and 50°C, and EGTA did partially at 50°C. Endogenous TGase catalyzed HC polymerization even at 50°C in the presence of E-64. Optimum temperature of TGase was around 40°C, however, high activity remained even at 50°C.