In this work, a novel electro-optic crystal KLi(HC3N3O3)·2H2O was explored by powder method. The contribution of lattice vibration was calculated by infrared reflectance spectrum and Raman spectrum. The effective nonlinear optical coefficient was estimated from the powder second harmonic generation response. Consequently, the electro-optic coefficient of KLi(HC3N3O3)·2H2O is determined to be 2.37 pm/V, which is comparable to that of commercial β-BBO. The crystal was grown by aqueous solution method. Superheating and supercooling curves were measured for different raw materials. A transparent crystal with size of 35 mm×25 mm×10 mm was obtained after optimizing the growth process. The relationship between crystal morphology and anisotropic growth rate was confirmed by means of X-ray orientation and piezoelectric coefficient measurement.