Abstract: Drag-type wind turbine blades for wind-driven electricity generators are vertically provided between plates of the generator. The wind turbine blades have a plate-like structure with a fin-shaped surface. The turbine blade comprises a wind receiving side consisting of a base section, a base concave-shaped wind receiving section, a convex-shaped wind streaming section, and a wind streaming side of a convex-shaped surface extending in a radiation direction on the back of the wind receiving side. The base end of the wind receiving side and the connecting side comprise an inverse parabolic concave-shaped connecting section to connect it to the base section of the wind streaming side.