Ammonium dihydrogen phosphate (ADP) is an excellent inorganic nonlinear optical material with different device applications. In the present work, single crystal of pure ADP crystal has been grown from the aqueous solution by slow evaporation technique. The grown crystals have been subjected to various characterizations studies like UVvisible, FTIR spectroscopy and dielectric studies. FTIR spectrum analysis confirmed the presence of functional groups of ADP crystal. UV- visible studies suggest that the crystal is suitable for nonlinear applications. Dielectric studies confirmed the single phase and high purity of the crystal. During the growth it has been observed that the low evaporation rate gives good quality crystals.