Objective: To study the survival of Lactobacillus bulgaricus in Lactobacillus fermented milk before and after the addition of milk fat globule membrane (MFGM) enriched whey protein powder (M-WPI)， the flavour of the fermented milk and the antioxidant capacity of the fermented milk. Metabolomics was used to analyse significantly different metabolic markers and their pathways of action in Lactobacillus bulgaricus fermented milks before and after addition of M-WPI. Methods: Differential metabolites in the metabolism of fermented milk before and after the addition of M-WPI were identified by means of principal component analysis of the samples， partial least squares discriminant analysis， heatmap analysis and KEGG enrichment analysis， and in this way the effects produced by M-WPI on the fermented milk were analysed. The results showed that the addition of M-WPI to skim milk increased the survival rate of Lactobacillus bulgaricus and increased the flavor and antioxidant activity of fermented milk. Principal component analysis(PCA) and partial least squares discriminant analysis(PLS-DA) were used to determine a total of 77 significantly different metabolites， involving 19 major metabolic pathways. Among them， glucose， galactose， and other metabolites were up-regulated， which improved the survival rate of Lactobacillus bulgaricus； capric acid and malic acid could effectively improve the taste and flavor of fermented milk. Alanine， aspartic acid and pantothenic acid were involved in β-alanine metabolism， which was related to the increase of antioxidant activity of fermented milk. This study provides a reference for the nutritional evaluation of the inclusion of M-WPI fermented milk as well as the development of related processing technologies and products.