In order to investigate the effect of microencapsulation on the quality of fish oil， we made microcapsule by spray drying method， which was composed of chitosan as shell material， tuna oil as core material. The physicochemical properties， fatty acid composition and volatile ingredients were detected， and the accelerated storage tests were used to examine changes in these indicators above. The results showed that the fish oil microcapsules had higher peroxide value， lower unsaturated fat content， more key volatile components related to the fishy smell， and lower quality relatively. During the storage， fish oil microcapsules can significantly inhibit the increase of peroxide value and the increase of the content of key volatile components， and little effect on retention rate of DHA and EPA. Although the fish oil microcapsule preparation process will reduce the quality of fish oil to a certain degree， but to delay the oxidation of fish oil and masking bad taste does have a certain effect.