To provide a beam pipe joint structure of a guard fence which improves appearance by improving a conventional beam pipe joint structure of the guard fence, and which the versatility of a bracket in use.

The bracket 2 comprises a bracket body 10 and a reinforcing member 11. In the bracket body 10, a support mounting portion 10a is provided at the side of the support 1, and a beam pipe mounting portion 10b is provided on a road side. The reinforcing member 11 has a back portion 11a which is inscribed inside the support mounting portion 10a while having lateral portions 11b and 11b at both the sides of the back portion 11a, respectively, and inserted into the bracket body 10. The bracket 2 is fixed to the support 1 by fixing the support mounting portion 10a and the back portion 11a by means of a bolt 5 passing through the support 1. An inner sleeve 3 and ends of two beam pipes 4 and 4 which are fitted into the outer periphery of the inner sleeve 3 and abut against each other are bolt-joined to the beam pipe mounting portion 10b.