To provide a cobble stone masonry block constituted by a manufacturing construction method for forming a surface of a cobble stone into a smooth and uniform face when constituting a lump of a stone masonry block composed of natural stones using cobble stones having unequal shapes and dimensions and integrating them as an earth retaining wall for use.

Cobble stones 2 having unequal shapes and dimensions are spread on a bottom face to form like dry stone masonry in a box frame 1 forming a lump of the cobble stone masonry block 14 having width B, length L, and thickness H, and sand 3 is charged into a cavity part having thickness h1 from the bottom face through a clearance in dry stone masonry to fill and bury it. Next, a cylindrical member 4 forming a hole in which a main bar 5 for connection is inserted, a cylindrical member 8 forming a blow hole, and reinforcing bars 6 are arranged to place concrete 7 into the cavity part having thickness h2 of an upper part. After hardening, the box frame 1 is dismantled and sand 3 is removed to form a face of slope on which the surface of cobble stone masonry block is smooth and uniform easily.