A study was made of the mechanical properties of Mo-base binary alloys containing Al, Co, Cb, Ti, and V. The 0.75% Cb alloy in the stress- relieved condition and the 1.26% Ti alloy in the fully recrystallized condition exhibited greater stress-rupture life than other alloys tested. A minimum of 0. 10% Al resulted in adequate deoxidation of acceptable Mo powder melted in A. A high degree of transverse ductility was obtained in the C-vacuum ingot containing a small amount of Zr. A survey was made of Mo-base ternary alloys containing 0.16% Al and increasing amounts of Co, Cb, Ti, V, and Zr.