As one of the studies on the recovery and recrystallization processes of statically and dynamically cold-worked metals, the release of stored energy of statically or impactly compressed commercial aluminium has been measured. Except at small compression, all of the released energy versus temperature curves of both statically and impactly compressed specimens have a shoulder and three peaks respectively, but the forms are different with the compression methods. That is, the higher the peak temperature, the larger the value of the peak under impact compression, but under static compression, the values of peaks under small compressions decrease with the temperature, while the values under large compressions become larger with the temperature. Then the total released energy under static compression is somewhat larger than that under impact compression, but both increase with the degree of compression. On the structure of the comparatively large compressed specimens was found an anisotropic growth of sub-grains by heating up to the second peak temperature and of recrystallized grains by heating up to the third peak. The first peak near 120°C in the released energy curve may be attributed to the extinction of vacancies and interstitials and to the formation of Cottrell’satmosphere of impurities. The second peak is attributed to the sub-grain formation due to the rearrangement of the dislocation forming Cottrell’satmosphere, and the third peak to the recrystallization. These results agree closely with the phenomena found in the room-temperature internal friction change of cold-compressed aluminium by the repeated annealing.