Model reference non-linear control (MRNC) of non-linear systems with input multiplicities is analysed. The system is a continuous stirred tank reactor (CSTR) carrying out Van de Vusse reaction schemes. The system has two values of an input (u) to get a desired value of an output (y). A MRNC designed based on the original state variable model equations drives the system input to a larger value rather than to a smaller value. Whereas the MRNC designed based on a pseudo dynamic model equation drives the system input to either smaller value or to a larger value depending on the designer＇s choice.