In this paper, we have investigated the possibility of using TiB2 particles to promote reinforcement strengthening in niobium. Niobium obtained from the. HDH process and TiB2, both in the powdered form, were mixed, cold pressed and sintered in high vacuum in temperatures ranging from 1300 to 1900 degreesC for 4 hours. In this paper we present and discuss the results concerning the microstructural evolution during high-vacuum sintering of niobium with additions of TiB2 up to 2 wt-%. Aspects related to phase stability and chemical composition of the resulting alloys will be discussed. Results show that dissolution of TiB2 particles becomes significant above 1400 degreesC. After sintering at 1900 degreesC, the smaller TiB2 particles are fully dissolved whereas the larger ones are partially dissolved. Dissolution of TiB2 particles occurs with the formation of Nb-Ti solid solution and NbB phases.