The method and system of hands-free telephone system for a vehicle increase the convenience of making a call on a portable phone and improve the safety of making the call while driving a vehicle that comprises: a memory section for storing a telephone number; a voice recognition module for receiving voice and recognizing it; a voice synthesizing module, wherein the voice synthesizing module outputs the voice according to an instruction of the voice recognition module or character information displayed on a portable phone; a control section for receiving a signal from the memory section and the voice recognition module to control them; an input/output module for inputting or displaying a telephone number of the portable phone; and a Bluetooth communication module for transmitting voice and character information by wireless communication and so as to make a voice speech and output it in voice according to the voice and character information. |