To provide a repair joint for underwater cables, provided with a cable bend preventing function so constructed that when an underwater cable is installed or lifted, local bending force can be prevented from being exerted on the underwater cable at a cable inserting portion of a protective tube in an underwater cable junction.

The repair joint for underwater cables includes a protective tube 15 that protects a cable junction 5; and a clamp fitting 17a having a fixed portion 18a to be fixed on one end of the protective tube 15 and a clamping portion 21a that clamps an underwater cable 1a. The cable junction 5 is encircled and protected with a metallic conduit 8 in the protective tube 15, and a waterproofing intimate mixture 16 is filled in the following gaps: the gap between the protective tube 15 and the metallic conduit 8; the gap between the metallic conduit 8 and the cable junction 5; and the gap between the clamp fitting 17a and the underwater cable 1a.