A power consumption control apparatus and a method thereof in the PDA phone comprise: transiting the PDA phone from an idle mode to a sleep mode automatically after a certain amount of time or by user's input signal; transiting the PDA phone from a called mode to the sleep mode automatically after a certain amount of time or by user's input signal; transiting the PDA phone from a calling mode to the sleep mode automatically after a certain amount of time or by user's input signal; and transiting the PDA phone from an in-call mode to the sleep mode automatically after a certain amount of time or by user's input signal, so that the power consumption control apparatus and the method thereof in a personal digital assistant (PDA) phone in accordance with the present invention can reduce power consumption of the PDA phone by transiting the PDA phone from a called mode, an in-called mode and a calling mode to a sleep mode, and cope with the circumstances which may occur in every state of the PDA phone.