In this work, a Ti₂AlNb based intermetallic alloy with the composition of Ti-22Al-24Nb-0.5Mo (at. %) pre-alloyed powder was produced by gas atomization, then fully dense powder metallurgy (PM) Ti₂AlNb alloy was fabricated by a hot isostatic pressing (HIPing) route. Powder size distribution obviously affected the porosity distribution of PM Ti₂AlNb alloys. The weld porosity and inclusion were not found in the as-HIPed Ti₂AlNb rings to be electron beam welded according to the X-ray radiographic inspection. The microstructure of as-HIPed Ti₂AlNb compacts was characterized by optical microscopy (OM), scanning electron microscopy (SEM), X-ray diffraction(XRD) and so on.From the fusion zone to the parent material, the microstructure changed from the single phase (B2) to duplex (α₂ B2 O phase). The microhardness of fusion zone and heat affected zone were higher thanparent material.