To further understand the thermal stability of fish collagen in solution, the thermal denaturation of collagen from the skin of snakehead (Channa argus) was studied by differential scanning calorimetry. Iso-conversional and multivariate non-linear regression (Multivar-NLR) methods showed that the thermal denaturation behavior of fish skin collagen solution (FSCS) could be best described by a three-state model (a reversible step followed by an irreversible one), which approximated to single-step process at low heating rate (beta) or low temperature. FSCS had relatively lower denaturation temperature (T-max), enthalpy and apparent activation energy than bovine hide collagen under the same conditions. Based on Multivar-NLR, T-max(beta=0.001K/min) of FSCS was simulated to be 21 degrees C, comparing with Tmax(beta=2-8 (K/min)) (30.4-32.2 degrees C); however, the optimal operating temperature of FSCS would be below 10 degrees C for anti-denaturation, indicating that FSCS should be handled at much lower temperature than conventionally determined. (C) 2014 Elsevier B.V. All rights reserved.