The　objectives　of　this　study　are　to　evaluate　the　variables　that　affect　the　shear　behavior　of　unreinforced　masonry　(URM)　walls　and　to　propose　the　equation　of　the　rocking　and　toe　crushing　strength　of　URM　walls　by　regression　analysis　using　the　test　data　including　the　previous　research.　The　main　variables　are　the　axial　stress,　the　aspect　ratio　and　the　thickness　of　URM　walls.　The　test　results　show　that　the　specimens　are　governed　by　rocking　and　toe　crushing　failure　modes.　The　relationship　of　the　shear　strength　is　proportionate　to　the　square　root　of　the　vertical　axial　stress,　and　the　relationship　of　the　shear　stress　and　aspect　ratio　is　linearly　proportional.　Shear　strength　and　cross　sectional　area　are　not　proportional.　For　the　URM　walls　tested.　the　proposed　rocking　and　toe　crushing　strength/actual　strength　ratio　of　0.95,　and　coefficient　of　correlation　R　of　0.9889　are　more　appropriate　than　the　FEMA　306　rocking　and　toe　crushing　strength　formulas.