The TiB 2 particles reinforced NiAl alloy composite was fabricated by hot-pressing aided exothermic synthesis (HPES). The interface between TiB 2 reinforcement and NiAl matrix and the precipitate in composite were studied by transmission electron microscopy (TEM). The experimental results show that there is no reaction product formation at the TiB 2 /NiAl interface and the relationships between TiB 2 and NiAl have no specific orientations. In addition, a fcc phase with lattice constant a=1.05 nm precipitated in TiB 2 /NiAl composite. TEM energy dispersive X-ray spectroscopy analysis of this fcc phase indicated that it contains element Ni, Al and B with near atomic ratio 20:3:6, thus, this fcc phase is a boride, Ni 2 0 Al 3 B 6 .