PURPOSE: To make the structure of a form for molding corner blocks for retaining simple and cope with the requirements irrespective of the angle made by a retaining wall.

CONSTITUTION: An outer frame A is composed of plane members 11, 12 and a flexible member 13 which is connected with the plane members 11, 12. An inner frame B is also composed of plane members 21, 22 and a flexible member 23 which is connected with the plane members 21, 22. The outer frame A is bent at an objective angle to be fixed to a bottom frame C, and a side frame D is fixed to the outer frame A and the bottom frame C. An end frame F is installed at need. The inner frame B is bent at an aimed angle to be fixed to the outer frame A and the side frame D, and concrete is cast from an opening formed at the upper ends of these frames A, B, D. An interior frame 51 having a design made of inclination or unevenness is attached to the outer frame A. In this case, inclination or a design can be applied on the surface of a molded corner block.