Elemental powder mixtures of TixSi100−x were mechanically alloyed by using a planetary ball mill. XRD, SEM, TEM and DTA were used to characterize their mechanical alloying process. After milling for 45 h, Ti75Si25, Ti62.5Si37.5 and Ti50Si50 powders were amorphized completely; however, no obvious amorphization was observed for Ti33.3Si66.7 and Ti25Si75 powders. By using Miedema model, a thermodynamics analysis was performed. Annealing the as-milled powders in vacuum at 860°C for 1 h, the as-milled Ti62.5Si37.5 powders transformed into Ti5Si3 intermetallics, and Ti33.3Si66.7 transformed into TiSi2 intermetallics completely.