Abstract: The invention provides a fat composition enriched with medium-and long-chain triacylglycerol and its preparation process. As for fatty acid composition, the content of medium-chain fatty acids and long-chain fatty acids reach above 99%, the content of short-chain fatty acids is less than 1%, and the mass ratio of long-chain fatty acids to medium-chain fatty acids is from 1.2:1 to 3:1. As for triacylglycerol composition, the triacylglycerol containing one medium-chain fatty acid and two long-chain fatty acids makes up 50-90% of the total triacylglycerol; the triacylglycerol containing two medium-chain fatty acids and one long-chain fatty acid makes up 3-35% of the total triacylglycerol; the triacylglycerol containing three medium-chain fatty acids makes up 0-10% of the total triacylglycerol. The fat composition has better oxidation stability and fat digestion and absorption rate, meeting the needs of particular groups of infants and young children.