Transparent fresnoite(Ba2TiSi2O8) glass-ceramics considered as a new type of non-linear optical materials have been prepared by controlled heat treatment in the system xK2O-(33.3-x)BaO-16.7TiO2-50SiO2(0≤x≤20 mol%), and optical properties were investigated. The glassy nature was analyzed by differential thermal analyses. The transparency of glass-ceramics was variable and controllable by the processing parameters like time and temperature. The transparent glass-ceramics showed second harmonic generation (SHG) when irradiated by a 1064nm laser beam (Nd:YAG). The SHG intensity was compared with a Y-cut α-quartz plate.