We investigate optical bistability (OB) and optical multistability (OM) behaviors in a triply driven five-level atomic system. It is shown that the system has bistable behavior and can be controlled by intensity of applied fields. We find that OB switches to OM via interference induced among the Rabi-split resonance. We consider a superposed one-dimension standing wave, generated by two optical fields, and it is demonstrated that the OB and OM behaviors depend on the position of localized atoms as well as the relative phase of applied fields.