An apparatus and a method for controlling uplink power utilizing an open-loop scheme in a mobile communication system using a TDD scheme. According to the apparatus and the method, an AT determines initial uplink transmit power and transmits uplink signals to an AP using the determined initial uplink transmit power, receives downlink signals from the AP, detects a power compensation value compensating for the uplink transmit power, which are determined according to whether an error has occurred in the uplink signals, measures receive power of the downlink signals, and adjusts the uplink transmit power according to the receive power and the power compensation value.