A novel reduction process by spark plasma is proposed for the synthesis of homogeneous intermixed ZrB 2 – SiC – ZrC nanostructure powder using ZrSiO 4 , B 2 O 3, C and Mg as starting materials. In the present research, the reaction mechanisms were investigated by the displacement –temperature – time (DTT), the displacement rate – temperature and the displacement rate – time diagrams which were obtained during spark plasma cycles. The synthesis process of the composite was completed after 15 min at temperature of 400 1 C. The total shrinkage of 5.5 mm was observed due to the rearrangement and reaction phenomenon. The main shrinkage occurs within a period of less than 1 min at 400 1 C similar to the self propagating high temperature synthesis. Finally using Rietveld method, the mean crystallites sizes of about 26, 25 and 22 nm were calculated for ZrB 2 , SiC and ZrC phases, respectively.