Ca films were deposited directly on Si(100) substrates by Radio Frequency (R.F.) magnetron sputtering system (MS) and subsequent were pre-annealed at 600 °C for 2h in situ. Finally, the samples were annealed again at 750°C, 782°C, 795°C, 800°C and 850°C for 1h in a vacuum furnace by an interdiffusion process between the deposited particles and clusters and Si atoms, respectively. The structural and morphological features of the resultant films were tested by XRD, SEM, EDAX and FT-IR. The cubic phase Ca 2 Si film and the tetragonal phase Ca 5 Si 3 film were grown directly and individually on Si(100) substrates, respectively. The experimental results indicate that the selective growth of a single phase Ca-silicide in Ca-Si system in the existence of multiple silicide phases depends on sputtering condition and annealing in twice. In addition, the electronic structure of stressed the cubic phase Ca 2 Si was calculated using the first-principle methods based on plane-wave pseudo-potential theory.