For a finite dimensional slab of cold energy storage, the ice freezing process inside itat different freezing temperatures were theoretically investigated by adopting a combinationmethod of analytical and integral solutions. Through this study, the formulas predicting thetimely variation of ice-water interface position, the transient heat flux on the slab boundaryand the amount of clod energy stored into the slab during a freezing period were obtained-Meanwhile, the influences of freezing temperature and thickness of ice on the phase-changerate, heat fiux and charging time of the slab were also discussed in detail.