Twelve-four Sunit lamb were equally allocated into two groups， which were fed a basic diet alone or supplemented with Lactobacillus. The effect mechanism on fat distribution and fatty acid profile of Sunit sheep was studied by measuring their fat distribution， fatty acids profile and metabolomics of longissimus thoracis (LT) and tail fat (TF). The results showed that the fat content of LT and biceps femoris (BF)， the content of myristic acid and docosahexenoic acid in LT and BF， palmitic acid， γ-linolenic acid and arachidonic acid in LT， monounsaturated fatty acid， palmitoleic acid and oleic acid in BF， cardamom oleic acid in subcutaneous fat(SF)， trans-oleic acid， trans-linoleic acid and α-linolenic acid in TF were significantly higher than that in the control group(P<0.05). The fat content of abdominal SF and the proportion of TF， the content of trans-linoleic acid in LT and BF， lauric acid in BF and SF， palmitic acid in SF were significantly lower than those in the control group (P<0.05). At the same time， significant changes in choline metabolism and fatty acids metabolism pathways of LT and TF were found based on metabolomics. Specifically， the levels of phosphocholine and cytidine diphosphocholine in LT of were significantly higher than those in control group， but the TF was opposite (P<0.05). The levels of oleic acid， α-linolenic acid in LT and palmitoleic acid， γ-linolenic acid in TF were significantly lower than those in control group (P<0.05). In conclusion， Lactobacillus affected the choline and fatty acid metabolic pathways of Sunit sheep to a certain extent， and then improved its fat distribution and fatty acids profile.