To efficiently perform work for protecting a face-of-slope by arranging plural concrete blocks in a line and lines of concrete blocks in multistage zigzag shape and connecting lines and stages of concrete blocks one another with vertical reinforcing bars.

Plural concrete blocks 2 are arranged in a line, lines of blocks 2 are arranged into multistage zigzag shape and lines and stages of blocks 2 are connected one another with vertical reinforcing bars 5 passed through stages of blocks 2 in the vertical direction to form a concrete block aggregate 1. The aggregate 1 is built in a face of slope of a banking 22A and the reinforcing bar annular portions 3 are matched to the face-of-slope annular portions of grid reinforcing bars 21A to pass locking reinforcing bars 23A therethrough for temporarily fixing the aggregate 1 on a natural ground. The upper aggregate 1 is set up on the backing 22A and the lower aggregate 1 is fixed on the natural ground with two locking reinforcing bars 23A, 23B and two grid reinforcing bars 21A, 21B. In this way, the face of slope is protected by the aggregates 1 and construction work is efficiently performed.