It is well known that Ni₃Si intermetallic compounds have an excellent corrosion resistance in H₂SO₄ solution. However, practical production has been difficult because of poor ductility caused by very brittle phase which is liable to be formed. Therefore, the process conditions involving a mechanical alloying(MA) technique were investigated in order to obtain final products composed of Ni₃Si stoichiometric single phase compo-und by suppressing the formation of brittle phase. In this paper, fine Ni-Si composite powders which have been prepared by the MA method were hot extruded, thereafter β phase - Ni₃Si consolidates were obtained by a specific heat treatment. The influence of compositions, MA conditions and heat treatment conditions for obtaining the β single phase - Ni₃Si intermetallic compounds were investigated. It was confirmed that consolidates of Ni₃Si intermetallic compounds with almost single phase(β phase) can be obtained under the following conditions: composition of 13.1 mass%Si and 86.9 mass%Ni, MA(B/P=16) for 346ks, extrusion at 1223K and heat treatment at 1223K for 18ks.