Disclosed herein is a photonic crystal waveguide inlet structure for improving coupling efficiency of a strip waveguide and a photonic crystal waveguide. The photonic crystal waveguide inlet structure includes an inlet region of the photonic crystal waveguide. The photonic crystal waveguide includes photonic crystals in which air holes are arranged in a triangle lattice shape in a dielectric, and a hybrid waveguide in which at least one of the air holes is removed, the hybrid waveguide spacing the inlet region apart from the strip waveguide.