Milk powders for middle-aged and elderly with different proportions (0%, 0.5%, 1.0% and 1.5%) of fish oil microcapsules were stored under accelerated conditions at 37 ℃ for up to 90 days. Their stability was evaluated by measuring changes in fatty acid composition, contents and retention rates of vitamin E and vitamin C, thiobarbituric acid reactive substance (TBARs) value and color during the storage period. The results showed that the addition of fish oil microcapsules had a certain effect on the stability of fatty acids in milk powder, but this effect did not show a consistent increasing or decreasing trend with the amount of added fish oil powder. The stability of fatty acids in milk powder was decreased by adding a high proportion of fish oil microcapsules; the contents of C12:0, C14:0, C16:0 and cis-9 C18:1 decreased with storage period, while the content of trans-9 C18:1 increased. Meanwhile, fish oil microcapsules decreased the retention rate of vitamin E (when added in a high proportion) and vitamin C (when added in a low proportion), increased TBARs value, a* and b*, and decreased L* of milk powder during storage. However, in general, the effect on all the above parameters except the retention rate of vitamin C was marginal. In conclusion, fish oil microcapsules can be used in milk powder for middle-aged and elderly people, meeting the requirements for the shelf stability of milk powder for middle-aged and elderly people.