To provide a retaining wall unit displaying excellent design properties even after the execution of assembly and hating superior workability and manufacture thereof.

A plurality of decorative stones 11 are arranged in a wall shape while the design surfaces of the decorative stones 11 are exposed in three dimensions, and the rear sections of a plurality of the decorative stones 11 are fixed integrally by concrete 13. The retaining wall units 1 for the assembly type retaining walls have opposed surfaces 10 formed of concrete 13 and disposed opposite to the adjacent retaining wall units 1 at the time of assembly, and the front end sections 111 of at least one decorative stones 11 in the decorative stones 11 arranged at the end sections of the retaining wall units 1 are disposed under the state, in which the front end sections 111 are projected from the opposed surfaces 10, at that time.