This paper proposes extremum seeking control (ESC) schemes for Multi-functional Variable Refrigerant Flow (MFVRF) system under different operational modes@ in order to maximize the efficiency provided the satisfaction of thermal comfort. Extremum seeking control is a model-free control method@ which can search for unknown and time-varying optimum input(s) that can optimize a given performance index without the need for plant model. There are five operational modes considered in this study@ including Cooling Only@ Heating Only@ Cooling Dominated@ Heating Dominated@ and Heat Recovery mode. For all cases@ the zone temperature setpoint is achieved by controlling the respective IDU fan speed@ and the feedback required is the total power consumption of the compressor motor@ ODU condenser fan and IDU evaporator fans. For different operational modes@ the ESC inputs are chosen to be different combinations of compressor suction pressure setpoint@ ODU fan speed@ bypass flow valve opening@ superheat setpoints for IDU??s and ODU. To evaluate the proposed control strategy@ a Modelica based dynamic simulation model is developed for the multi-functional VRF system considered. Simulation results demonstrate the capability for the ESC to achieve the optimal operation in model-free fashion@ as well as the potential for energy saving.