Mixtures of W and B13C2 powders were mechanically milled and subsequently annealed at 900-1200℃.It is found that amorphous W-B-C alloy formed as the mixtures were milled for 20-80 h.After annealing the 80 h-milled mixtures at 900-950 ℃,solid solutions of C and/or B in tungsten [W(B,C)],C in tungsten boride [W2B(C) or WB(C)] formed by the crystallization of amorphous W-B-C.The formation temperature of W2B(C) and WB(C) is lower than that of W2B and WB reported previously.As the 80 h-milled mixtures were annealed at 1200 ℃,W reacted with amorphous W-B-C completely to form WB and W2B5 or W2B5 instead of the solid solutions of C in tungsten borides,which is determined by the mole ratio of W to B13C2.The formation mechanisms of the W2B(C) and WB(C) solid solutions as well as phase transition rules of the mixtures at annealing temperature and mole ratio were also investigated using first-principle calculation.