The volatile aromatic components in cow's milk and goat's milk yoghurt were extracted by solid-phase micro-extraction (SPME) and were analyzed by GC/MS. The results show that total 48 different compounds are isolated and identified from cow's plain yoghurt, and 50 different compounds are isolated and identified from goat's milk plain yoghurt. These compounds are carboxylic acids, alcohols & furans, aldehydes, ketones, esters, hydrocarbons, nitrogen-containing compounds, sulfur-containing compounds etc. The main volatile aromatic components of these two types of yoghurt are 2,3-Butanedione, 2-Furanmethanol, 3-hydroxy-2-Butanone etc. The types of volatile aromatic constituents in yoghurt both cow's and goat's milk are similar. However, the contents of these different aromatic compounds are different.