Abstract: An improved bathroom assembly construction includes a base, a plurality of corner posts, plates and partition strips, a roof, a plurality of corner caps and a plurality of securing means. Both the base and the roof are provided with corner slots, mounting slots and indentations for mounting respectively the corner posts, plates and partition strips to eliminate use of screw bolts. The corner posts may extend from the corners of the roof with the corner caps fitted thereon and may be secured firmly by means of the securing means. A gap is formed between two adjacent plates and is of a size matching that of a gap formed between two adjacent tiles so that, after tiles are arranged on the plates each of which has a width equivalent to a total width of a plurality of tiles, the bathroom assembly may look very neat.