Abstract: In order to improve the quality,nutrition and quantitatively evaluation,and quantitative assessment the effect of collagen peptide on set-style yoghurt,the set-style yoghurt samples with varied amounts of collagen peptide(0,0.2%,0.4%,0.6%,0.8%,1.0%,2.0%,3.0%,4.0%,5.0%)were prepared,and the related quality indexes were measured. The results indicated that collagen peptide enhanced the water holding capacity and pH value,the hardness,adhesiveness,gumminess,chewiness,and titratable acidity reduced,and prolonged the fermentation. However,no influence on springiness and cohesiveness was found. The ability of the collagen peptide affecting the quality of the yoghurt was directly constrained by its addition amount. In the cases of the addition amount ≤ 0.6%,significant variation of the quality of the yoghurt was observed as the addition amount increased. Whereas,the quality of the yoghurt varied slightly as the addition amount increased continuously when over 0.6%. The variation of the quality of yoghurt could be ascribed to the damage to the inter-protein crosslinking caused by the added collagen peptide. Moreover,a series of empirical models of dozens of assessment indices was developed,which reflected the quantitatively effects of collagen peptide on the quality of yoghurt,and would provide the theoretical foundation to the industry production of the yoghurt.