Thermal stability of sarcoplasmic protein and myofibrillar protein extracted from fresh and frozen common carp was comparatively studied. Total sulphydryl content (SH) in sarcoplasmic protein solution from 5-month frozen carp decreased by 19.43% compared with fresh sample. The SDS-PAGE patterns showed that all the bands of sarcoplasmic protein from frozen-stored samples were almost invisible at 80°C. Myofibrillar protein from fresh sample exhibited lower turbidity and surface hydrophobicity and higher Ca 2+ -ATPase activity and SH content than frozen-stored sample when heated from 20 to 80°C. The Ca 2+ -ATPase activity from fresh (M0), 2 (M2)-and 5 (M5)-month frozen-stored carp was completely lost at 48, 46 and 46°C, respectively. When heated to 80°C, the SH content of myofibrillar solutions in M0, M2 and M5 decreased by 26%, 60% and 70%, respectively. Sarcoplasmic and myofibrillar proteins from frozen carp were more susceptible to aggregate during heating treatment.