PURPOSE: A sofa capable of changing armrest is provided to change armrest of a sofa by preparing a simple combining structure enabling a stable coupling between bases. CONSTITUTION: A sofa capable of changing armrest comprises a base(110) which is installed in the bottom side and supports the load of a user; a seat back(120) built in the back-end of the base; an armrest(130) which detachably combined with at least one of left and right ends of the base; a first inclined plane(111); a second inclined plane(131) facing the first inclined plane; a pair of coupling members(170a,170b) for coupling the base and armrest; and a spacer member(180).
