Glycinium Phosphite (GlP) has been synthesized and characterized successfully. The fluorescence spectrum of the compound showed one broad peak at 282 nm. Linear absorption value was calculated by Optical Limiting method. Birefringence study was carried out and the birefringence of the crystal is found to be depending on the wavelength in the entire visible region. Third order nonlinear optical property of the crystal was carried out by Z-Scan technique and non linear refractive index and third order susceptibility was calculated. Thermal stability of the crystal was found using TG and DTA thermal analyzer and the results shows that the crystals have good thermal stability. The crystal was also analyzed by photo conductivity analyzer to determine the optical conductivity of the crystal.