Abstract: A lightweight interior sidewall and a method for fabricating the same are provided. The lightweight interior sidewall is formed by a plurality of adjacent slabs. A method for fabricating the slabs includes forming a concrete block made of cement, fine sand, bamboo-shaped short fibers and a lightweight aggregate material, cutting the block to form multiple slabs, and grinding a central region of two sides of each slab to form a longitudinal groove therein. The method for fabricating the lightweight interior sidewall includes disposing multiple slabs adjacent to each other, securing each slab between a reverse U-shaped clamp on the ceiling and a support element on the floor, and filling a cement mortar into the longitudinal grooves to bind the slabs together. The lightweight and robust sidewall can be thereby formed in an efficient manner.