The Ca3NbGa3Si2O14 (CNGS) crystal was grown by the micro-pulling down (mu PD) method and the annealing effect on physical properties of CNGS crystal was investigated in this study. And the effects of oxygen content on the physical properties were systematically studied. Additionally, Photoluminescence (PL)-Mapping and radioluminescence spectra of CNGS were observed. The absorption peaks were observed around 350 and 500 nm. This absorption at 500 nm was very sensitive to a quantity of excess oxygen in the CNGS crystal. In contrast, it is expected that the absorption of 350 nm is related to a cation or anion defect. PL-Mapping indicated the emission around 400 nm by excitation at 270 and 350 nm wavelengths. The emission at 400 nm is considered to originate from trapped electron at an anion or cation defect. The emission of the Alpha-ray excited spectra was very similar in comparison with PL-Mapping. (c) 2012 Elsevier B.V. All rights reserved.