The effects of pure grain feeding and feed mixed feeding on pork quality and flavor was studied.The sensory evaluation, the edible quality and the volatile flavor components of the pork were compared and analyzed between two groups.Result： (1) there was significant difference in marbling (p<0.01), color (p<0.01), flavor (p<0.01), juiciness (p<0.05) and tenderness (p<0.05) between the two groups, and no significant difference in appearance.(2) juice loss (p<0.05), cooking loss (p<0.01) of grain feeding group were significantly lower than that of mixed feed group.The value of water content (p<0.05), pH, L* (p<0.05) was higher than that of the mixed feed group.There was no significant difference in the centrifugal loss rate.(3) Electronic nose were used, the different smell of the pork was analyzed by PCA and discriminated by LDA.(4) The chemical constituents were analyzed by headspace solid-phase micro-extraction gas chromatography-mass spectrometry (HS-SPME-GC-MS).A total of 52 compounds were identified from pork volatile substances, and the compositions and contents of volatile substances were different in two groups.(5) Significant differences were found in the contents of intramuscular fat (IMF) (p<0.05) between the two groups.A significant difference in the quality and flavor were showed in the two groups.The pure grain feeding pork had better quality and flavor than the mixed feed.In addition, the pure grain feeding can accumulate more IMF.