Example embodiments are directed to a method of growing GaN single crystals on a silicon substrate, a method of manufacturing a GaN-based light emitting device using the silicon substrate, and a GaN-based light emitting device. The method of growing the GaN single crystals may include forming a buffer layer including a TiN group material or other like material on a silicon substrate, forming a nano-pattern including silicon oxide on the buffer layer, and growing GaN single crystals on the buffer layer and the nano-pattern.