To provide a joint structure of a framework capable of securing high joint strength.

In this joint structure of frameworks 1, 2, the frameworks 1, 2 having frame members 11, 12, 13 forming the outer edge are joined to each other while the outer surfaces of the frame members 11, 21 to be joined to each other are opposed to each other. Bolt holes 111, 211 are formed through the opposed frame members 11, 21 to be joined to each other. A recessed part 112 is formed in the inner surface of one frame member to be joined. A bolt 3 is inserted into the bolt holes 111, 211 and the frame members 11, 21 are tightened to each other. A nail member 4 of such a length that is driven into the opposed frame member 21 is driven from the recessed part 112 thereinto.