There is provided an optical connection structure in which an optical fiber and an optical semiconductor waveguide are easily connected with low loss. The present invention relates to an optical connection structure configured to connect an optical waveguide device and an optical fiber including cores having different refractive indexes, wherein an optical connection component using a planar lightwave circuit is bonded and fixed on an end surface of an input/output waveguide of the optical waveguide device, a value of a refractive index of a core of the planar lightwave circuit is between a value of the refractive index of the core of the optical waveguide device and a value of the refractive index of the core of the optical fiber, and the optical waveguide device and the optical fiber are optically connected via the planar lightwave circuit.