Single crystal growth of undope CaCl2, CaBr2 and CaI2 was performed by Bridgman–Stockbarger (BS) method. Investigations of their crystal phases, luminescence and scintillation properties such light yield, energy resolution decay time were performed. In addition, linearity of gamma-ray response in 32–1275keV range were also evaluated. The light output of 106,000 photon/MeV, energy resolution of 3.2%@662keV, and scintillation decay time of 834ns (84%) 1460ns (16%) were observed. Luminescence properties of CaBr2 also firstly reported.