In this paper， cod skin gelatin was used as raw material， and the effect of xylitol， sucralose， stevioside， sucrose on the physical， rheological， functional characteristics and Raman spectrum of fish skin gelatin was studied. Results indicated that sweeteners/ sucrose can improve the gel strength， hardness， thermal denaturation temperature and enthalpy of gel products. The results of rheology and functional properties showed that the sweeteners/sucrose could make the gel samples have higher G′， G″， foaming property and water holding capacity. Raman spectra illustrated that the protein secondary structure of the mixed system was transformed random coil into α-helix， which made the system more stable. Therefore， low-calorie sweeteners could be as the sugar replacers applied to food industry.