1Cr18Ni9Ti and Ti-6Al-4V were selected as the metal substrates, and CrO3+Al thermit was introduced into B4C+Ti primary system for adjusting the adiabatic temperature of reaction system as 3 193, 3 282, 3 290 and 3 473 K, TiB2-TiC/1Cr18Ni9Ti and TiB2-TiC/Ti-6Al-4V graded composites were prepared by reaction joining in high-gravity field. Because increasing reaction adiabatic temperature brought about the increased melting depth of metal substrates, the intermediate between the ceramic and metal increased in thickness while Al2O3 inclusions at the interfacial areas inevitably increased. By changing the processing route, i.e. respectively preparing, ball-milling and compacting B4C+Ti blends and CrO3+Al thermit and subsequently filling them one by one into the crucibles, it is found that Al2O3 inclusions at the intermediates are removed completely, three-dimensional network ceramic/metal graded composite structure develope in the interface of TiB2-TiC/1Cr18Ni9Ti, while in the interface of TiB2-TiC/Ti-6Al-4V there forms the multiscale and multilevel graded composite structure. © 2015, BUAA Culture Media Group Ltd.. All right reserved.