Potassium lithium niobate (KLN) crystals, grown by the micro pulling down $({mu}-PD)$ method, have been considered on the interchange between incongruent melt composition and second harmonic generation (SHG) properties because of the sensitive interaction. Correlation between the composition of crystals and the wavelength of SHG applications from ultra - violet to green region was found. Also, the ${mu}-PD KLN$ KLN crystals showed a homogeneity of noncritical phase matching and an excellent SHG property which is converted to blue laser light with half wavelength by the red irradiation.