Plate-shaped crystals of Li2MnO3, red-colored with glossy surface, were obtained over a tilted crucible by LiCl flux evaporation at 923 K for 5 days. The growth of the Li2MnO3 crystal plates proceeded at the interface of three phases, i.e. the LiCl flux, the precipitated powder, and the atmosphere on the tilted crucible. The moving solid-liquid-air interface due to the continuous evaporation of LiCl flux plays an important role in the growth of Li2MnO3 crystal plate.