Sodium p-nitrophenalate para nitro phenol dihydrate (SPPD) is a semi organic non linear optical crystal which has been synthesized. Single crystals (size 3x2.5x1.7mm3) have been grown by slow evaporation of the saturated aqueous solution. The Grown crystals have been identified from single crystal XRD analysis and FTIR spectroscopic techniques. SAAP was thermally stable up to 52°C as determined by TG/DTA curves. The crystal possesses prominent positive photoconduction in the presence of photoactive centers formed with trap energy levels. The non linear optical activity is confirmed by Kurtz powder test.