The trial was conducted to investigate the effects of breed, age and feeding regime on the contents of inosine-5′-monophosphate (IMP) and intramuscular fat (IMF) in chicken meat and the interactions among influencing factors. A total of 240 Arber Acres (AA) broilers and 240 Beijing fatty chickens were both divided into two groups fed in two feeding regime (in cages or on the floor, respectively), thus there were 120 chickens for each Feed style, which contained 6 replicates with 20 chickens each. On day 21 and 42, the IMP and IMF contents of chicken meat were compared and fatty acid composition was analyzed. The results showed as follows: 1) the IMP content in chicken meat of Beijing fatty chickens was higher than that of AA broilers (P<0.05), for which, 42-d-old chickens was higher than 21-d-old chickens (P<0.05), and there was a significant interaction between breed and age (P<0.05); 2) the IMF content in chicken meat of Beijing fatty chickens was higher than that of AA broilers (P<0.05), for which, 42-d-old chickens was higher than 21-d-old chickens (P<0.05), and chickens in cages were higher than those on the floor (P<0.05), and no interactions among breed, age and feeding regime were observed (P>0.05); 3) except C18∶0 and C22∶0, other fatty acid contents were significantly affected by breed; for C18∶2 and C24∶0, Beijing fatty chickens were higher than AA broilers (P<0.05), when it came to other fatty acids, it was reversed (P<0.05). The content of unsaturated fatty acids and its ratio to the content of saturated fatty acids in the meat of Beijing fatty chickens were higher than those of AA broilers (P<0.05); age had no effects on the composition of fatty acids in chicken meat (P>0.05); feeding on the floor significantly increased the content of saturated fatty acids and its ratio to the content of unsaturated fatty acids in the meat (P<0.05); the interactions among the three influencing factors were not observed in the contents of fatty acids (P>0.05). So a conclusion can be drawn that IMP, IMF and fatty acid C18∶2 and C24∶0 contents in the meat of Beijing fatty chickens are significantly higher than those of AA broilers; IMP and IMF contents in the meat of 42-d-old chickens are significantly higher than those of 21-d-old chickens; the contents of IMF, saturated fatty acids C14∶0, C18∶0, C20∶0 and C22∶0, and the ratio of saturated fatty acids to unsaturated fatty acids in the meat of chickens fed on the floor are significantly lower than those of chickens fed in cages. There is a significant interaction between breed and age on the content of IMP in chicken meat.［Chinese Journal of Animal Nutrition, 2010，22（5）:1251-1256］