Abstract: To explore the reasons for the softening of the domestic chocolate balls, NMR, gas chromatography and Aw tester were employed to detect the solid fat content (SFC) and fatty acid composition of the internal and external layers and water activity in the wafer layer. The SFC in external layer of the domestic chocolate balls was lower than that of the imported chocolate balls (control) (except for 40℃) , and the SFC decreased along with the increasing of storage period (<20℃) . As to the SFC in internal layer, it decreased along with the increasing of storage period at the low temperature (<17℃) , but the trend was opposite at the high temperature (>17℃) . The main fatty acid contents in the external layer of the domestic products and the control were close to each other. The trans fatty acid of the domestic products was 1. 6 times of the control. The water activity in biscuit layer of the domestic products was higher and increased with the increasing of storage period. It could be concluded that the solid fat in external layer would move into the internal layer during the storage period, furthermore, the internal materials of the domestic chocolate balls and the reference were different, and these may be the reasons for softening.