An electric compressor and a method of controlling the same, the electric compressor including a detection unit for detecting a phase of refrigerant in the electric compressor, a connection unit wound at a position adjacent to a passage of a housing for movement of a refrigerant in the electric compressor, and a control unit for performing control according to the phase of refrigerant by differently controlling power applied to the connection unit in response to data detected by the detection unit. The method including aligning a position of a rotor after an electric compressor is turned on, determining whether a refrigerant is in liquid phase or in gas phase, preheating the refrigerant by applying power to the electric compressor according to the phase of refrigerant, and controlling the electric compressor such that the electric compressor is normally operated after the refrigerant is preheated.