Oil, proteins, organic acids and amino acids were produced from fish meat by sub-critical water hydrolysis. A reaction model for kinetics of sub-critical water hydrolysis was proposed to explain the generation of major products such as oil, cystine, alanine, glycine, and pyroglutamic acid in sub-critical water hydrolysis of fish meat. Since the reaction kinetics in sub-critical water hydrolysis of fish waste is complicated, a simplified model was developed. It shows relatively good agreement with the experimental results for a wide range of reaction temperatures.