A wall mounting bath accessory assembly contains a fixing member including an inner wall, an outer wall, and two side walls; the inner wall including at least one recess and a retaining fence; on a connecting corner of each side wall and the outer wall being fixed a first resilient lock block, and the first resilient lock block including a first arcuate projection; a base formed in a cover shape and including a groove in which an opening is formed so that the fixing member is received in the groove via the opening, the groove including two first positioning ribs, and each first positioning rib including a first engaging slot; the groove also including two second positioning ribs, and each second positioning rib including a second engaging slot formed on a top end thereof proximate to the opening.