The present invention relates to a retaining wall by using vegetation blocks and a construction method thereof. As the vegetation block and a connection block are mutually assembled and integrated, a stable retaining wall is formed. The retaining wall by using the vegetation blocks and the construction method thereof are provided to improve support force relative to earth pressure by an anchor installed at inclined surface through the connection block. The present invention comprises: a vegetation block in which a vegetation space is prepared, an outer insertion hole in which a width narrows towards the lower surface from the upper surface is formed at both lateral walls outside the vegetation space, and an inner insertion hole is formed at both lateral walls inside the vegetation space in a cross section shape same as the outer insertion hole; a connection block in which the height is same as the vegetation block, both lateral ends are inserted into the outer insertion hole, a penetration unit penetrating from the front side to the rear side is formed, and an insertion groove is formed at the inner side of the penetration unit in a concave shape downwardly; an anchor inserted into the inclined surface through the penetration unit of the connection block and stably fixing the connection block to the inclined surface as being inserted into the insertion groove; an adhesive for fixing the anchor to the inner part of the connection block by being filled in the insertion groove through the penetration unit and being hardened.