To perform reliable slip-off prevention of the connection part of a flexible protection pipe to protect an optical fiber and a communication cable.

A plurality of flexible protection pipes 1 having a given length are converged at two end parts by nozzle stubs 3 to form a unit pipe convergence body. The nozzle stubs 3 and 3 at the two ends of a unit pipe convergence body are intercoupled by a linear body 21 for preventing elongation. The flexible protection pipes 1 and 1 are interconnected at a mutual connection part for the unit pipe convergence bodies, the flexible protection pipes 1 and 1 are interconnected and the terminals of the linear bodies 21 and 21 for prevention of elongation are intercoupled by a slip-off prevention tool 30. This constitution prevents a slip-off of the flexible protection pipes 1 and 1 from a collar 2.