Orthogonal tests with collagen extraction rate and gel strength as dependent variables were conducted to ascertain the optimum conditions of heat treatment of fish scale jelly from grass carp fish processed by no pre-treatment,acid pre-treatment and enzymatic pre-treatment.The results showed that with extraction temperatures of 100℃ and extraction time of 2h,the ratio of fish scale to water was 1∶ 4.With acid pre-treatment,the ratio was 1∶ 5.The pH of water was 6 for no pre-treatment.This extraction temperature and extraction time could be used for processing fish scale jelly from different kinds of fish.However,the ratio of fish scale to water should be adjusted based on different collagen contents of different fish scales.Three different fish scale jellies processed in their respective optimum conditions had no significant differences in gel strength.They were also softer,smoother and more elastic in texture than the ordinary fruit jelly with fruit taste.Fish scale jelly processed by enzymatic pre-treatment had the highest collagen mass concentration,while no pre-treatment yield the highest viscosity and the best texture.Acid pre-treatment processing had the highest yield.The gelling temperatures and melting temperatures showed that fish scale jellies should be cooled below 10℃ and preserved under 20℃.These results provide a reference for the development of fish scale jelly.