Single crystals of La₄Mo₇O₂₇ have been successfully grown by the flux growth method H₃BO₃ as the flux in a plantium crucible using the starting materials of La₂O₃, H₃BO₃ and MoO₃ in a molar ratio of 0.16:0.16:0.68, in which H₃BO₃ acted as a flux. Transparent colorless crystals were obtained with size of 0.8 × 0.3 × 0.2 mm³ under the optimized crystal growth conditions: growth temperature of 727°C, growth time of 95 h and cooling rate of 0.5°C/hr. A well-developed morphology of the crystals was observed and analyzed. The preparation process of starting materials on crystal growth was investigated. The grown crystals were characterized by powder X-ray diffraction (PXRD), EDAX, SEM, UV-Vis, photoluminescence studies, thermal analysis, dielectric studies and second harmonic generation (SHG). The results are presented and discussed.