A network transmitting apparatus and a power saving method thereof are provided. The network transmitting apparatus includes a chip, a transformer, and a power regulating unit. The chip includes a detecting and controlling unit, an analog circuit, and a digital circuit. The detecting and controlling unit receives a received signal and detects the received signal and a state of the chip to generate a first control signal. The transformer has a first side coupled to the chip and a second side. The power regulating unit coupled to the detecting and controlling unit and a center tap of the first side of the transformer is used for receiving a voltage, generating a first regulated voltage according to the first control signal, and connecting the first regulated voltage to the center tap of the first side of the transformer, the analog circuit, and the digital circuit.