In this study, the basic nutritional composition, flavor nucleotides, free amino acids and volatile compounds in dorsal and belly meat of rainbow trout from Beijing, Xinjiang and Qinghai provinces were respectively analyzed and compared. The results showed that moisture content of rainbow trout in Qinghai region was significantly less than those in Beijing and Xinjiang region, but content of crude fat was significantly higher than those of the samples of Beijing and Xinjiang. The basic nutritional composition contents of dorsal and belly meat of rainbow trout in same region were different slightly. Meanwhile, the AMP content and free amino acids of dorsal meat of rainbow trout in same region were not observably different from belly meat, however, the IMP content of dorsal meat of rainbow trout exceeded markedly belly meat. On the other hand, contents of AMP, IMP and free amino acids of rainbow trout in different regions had significant differences, and the contents in samples of Xinjiang were the highest. The results of electronic nose showed that the aroma of rainbow trout in Beijing was similar to the rainbow trout in Xinjiang, and was different from that in Qinghai region. At the same time, the volatile odor of dorsal and belly meat could be effectively distinguished.Most of volatile compounds in rainbow trout meat detected by GC-MS were carbonyl compounds and alcohols. The relative contents of carbonyl compounds of rainbow trout in Qinghai region was remarkably higher than those in Beijing and Xinjiang, nevertheless, relative contents of alcohols was lower than the other two regions.