Laser-induced crystallization in glass is a new crystallization technique of glass materials. This article reports the progress in the patterning of nonlinear optical crystal lines on the glass surface by laser irradiation techniques. Two techniques for the patterning of crystal lines have been developed, i.e., rare-earth atom heat processing and transition metal atom heat processing, in which continuous-wave lasers such as Nd:YAG laser (wavelength: λ = 1064 nm) are irradiated onto the glasses containing rare-earth ions such as Sm³⁺ and Dy³⁺ or transition metal ions. We introduced these atomic laser heating techniques for the patterning of nonlinear optical crystals (BiBO₃, β-BaB₂O₄, Ba₂TiGe₂O₈ and LiNbO₃) and clarified the features (morphology, orientation, optical nonlinearity) of crystal lines.