To provide a layout structure of cooling water piping for vehicles, configured to effectively protect a boot from snow damage in a simple configuration without increasing the number of parts or complicating the structure.

A layout structure of cooling water piping 21 is configured as follows. Behind a radiator 12 arranged at a front end, a steering gear box 7 of a steering device, a rack shaft 13 extended in a vehicle width direction, and a tie rod 14 connected to both right and left ends of the rack shaft 13 are arranged. Connection parts with the rack shaft 13 and the tie rod 14 are covered with left and right bellows-like boots 15L, 15R, respectively. An engine and the radiator 12 are connected by two pieces of cooling water piping 21, 22. A metal pipe 21c of the cooling water piping 21 is arranged above the boot 15R.