A sufficient joint strength is easily achieved in a joint structure between a fiber-reinforced plastic and another member. A joint structure 10 is a joint structure between a first member 100 having a pillared end part 100a made of a fiber-reinforced plastic and a second member 200 different from the first member 100. The end part of the first member 100a is reversely tapered in an axial direction, while a joining member 300 is disposed along a reversely tapered form of the end part 100a. The second member 200 is provided in contact with an end face of the first member 100 and connected to the joining member 300. A plurality of fibers 110a substantially extending in the axial direction of the end part 100a of the first member 100 are provided within the end part 100a and disposed to form a larger angle with the axial direction of the end part 100a of the first member 100 as they are disposed to be closer to a surface constituting the reversely tapered form in a radial direction of the end part 100a.