In order to clarify the difference of key flavor compounds in stewed Tan lamb from different feeding patterns， 6 Yanchi Tan sheep were selected of each group from grazed， grazed + supplemented and concentrated， respectively. Determination of routine nutrient composition and sensory quality of Tan lamb from three feeding patterns， the flavor of stewed Tan lamb from different feeding patterns was detected by Heracles II ultra-fast gas phase electronic nose. The results show that： feeding patterns had no significant effect on water and protein content （P > 0.05）， but had a significant effect on fat content （P < 0.05）， the fat content of Tan lamb was the highest in the concentrated group and the lowest in grazed group. Feeding patterns had significant effects on sensory indexes （tenderness， flavor， juiciness and overall liking） and sensory quality score MQ4 of stewed Tan lamb （P < 0.001）. The sensory quality of stewed Tan lamb from grazed + supplemented and concentrated was better than in grazed group. According to relative odor activity value analysis， the characteristic flavor compounds of stewed Tan lamb in grazed group was ethyl hexanoate， the grazed + supplemented group was 2-heptanal， and the concentrated group was beta-pinene and 2-ethyl-4-hydroxy-5-methyl-3-furanone. Therefore， it was concluded that there were differences in flavor compounds of stewed Tan lamb from different feeding patterns， using Heracles II ultra-fast gas phase electronic nose could identify the Tan lamb from different feeding patterns.