The studied technology involves the compaction of a powder by magnetic pulse compression (MPC), followed by consolidation by spark-plasma sintering (SPS). The aim of this work was to identify the properties of a compact produced by MPC, ensuring the preservation of the nanostructure during subsequent consolidation. The Sintering of the compacts was carried out also in a dilatometer with the purpose to analyze comparatively the densification processes under regular sintering and SPS. The studies were conducted on the powder Al2O3 (produced by "Advanced Powder Technology", Tomsk), obtained by the explosion of aluminum wire in oxygen. According to the certificate, the powder specific surface is 35-40 m2/g. Arithmetic mean particle size of 36 nm. The X-ray studies show that the phase composition of the powder includes predominantly the δ-phase. To obtain the α-phase the raw material powder is heated in a muffle furnace up to 1300 °C - the temperature above the temperature of the δ-α phase transformation. The both types of powders were pressed: δ-Al2O3 was compressed both in a regular press, and by means of a uniaxial MPC, α-Al2O3 - only by MPC. The pressure under regular pressing was 185 MPa. The inner diameter of the mold was 10 mm. The thickness of the resulting compacts fluctuated around 2.5 mm. The thus-obtained compacts were heated in a dilatometer at a heating rate of 10°C/min up to different maximum temperatures. The maximum temperature at which the exposure was up to 4 hours, was 1550°C. The study of the properties of compacts during pressing and sintering at different stages were conducted using scanning electron microscopy (SEM), X-ray and thermal analyzer. After compression the compact structure consists of agglomerates. In turn, larger agglomerates consist of smaller agglomerates having nano-sized particles. These nano-agglomerates had dimensions of 150 nm for δ-Al2O3 and 250 nm for α-Al2O3 phases with a block size of coherent scattering of 22 and 95 nm, respectively. As a feature that distinguishes MPC from normal compression it should be noted that in α-Al2O3 after MPC the block size of coherent scattering has almost halved down to 49 nm. The MPC of δ-Al2O3 led to a marked increase in the alpha phase concentrationfrom 2 to 4.5%. In α-Al2O3 compacts after MPC the relative density during heating grew monotonically with the tendency to saturation at a maximum temperature of heating. In δ-Al2O3 compacts the temperature region of 1200 ° C is an important step, due to a phase transition, which is accompanied by the change in the mechanism of sintering. A distinguishing feature of the structure ofthe alpha-oxide processed by MPC compared to the delta-oxide after the classic compaction is a reduction in the block of coherent scattering after compaction and lower block size of coherent scattering in the temperature range of 1245 - 1450 ° C, despite the larger initial particle sizes, and a higher relative density achievable after heating . A distinguishing feature of the structure of the delta oxide processed by MPC in comparison with a classical compaction is an increase of the proportion of alpha-phase at low temperatures and slowing down of the grain growth up to the maximum temperature. In the both types of the powder compression and in the both types of sintered compacts an agglomerated structure is preserved. Mostly it is evident in the α-Al2O3 phase specimems after regular quasi-static compaction, the least evident this fact is - in the both species, for the powders after MPC treatment. Most large agglomerates that are larger than 20 microns, are likely broken. However, agglomerates and sintered mass between them consists of nano – agglomerates. The destruction of the agglomerated structure and merging the nano-agglomerates in the grain nuclei – are the two mechanisms that are responsible for the decrease in volume and increase in density in the both types of the compacts. The size of nano-agglomerates determines the minimum possible size of the grains during sintering. It is shown that MPС-treatment of nano - powders such as α-Al2O3, and δ-Al2O3 has a significant influence on the sintering mechanism. This fact can be used during the sintering of compacts in the SPS in order to preserve the nanostructure.