PURPOSE: To efficiently collect and drain rain-water by projecting a curbstone part in a shoulder part of a block main body, and providing drain ports passing through the inside of the block main body at a lower position of the curbstone part.

CONSTITUTION: A block main body 11, which is made of a concrete block having an inverted-U shape cross section, is formed. Holes 20 passing through the inside of the block main body 11 are provided in the top surface of the block main body 11, and an opening 23 is also provided in the top surface of the block main body 11. A projecting part having a nearly trapezoidal cross section, of which one surface is inclined to one side, is provided at a shoulder part of the block main body 11 to provide a curbstone part 12. Furthermore, drain ports 13 passing through the inside of the block main body 11 are provided at a lower position of the curbstone part 12.