An apparatus for echo cancellation in a transceiver of a full duplex communication system, where the transceiver includes a transmitter for transmitting a transmit signal and a receiver for receiving a receive signal, includes: an echo cancellation signal generator, coupled to the transmitter, for receiving the transmit signal and for generating an echo cancellation signal according to the transmit signal, wherein the echo cancellation signal reflects an effect of an impedance of a channel and a parasitic capacitor of the transceiver; and a calculation module coupled to the transmitter, the receiver, and the echo cancellation signal generator for receiving the receive signal and for canceling the echo of the receive signal according to the echo cancellation signal to generate an echo-cancelled signal, wherein the effect of the impedance of the channel and the parasitic capacitor of the transceiver in the echo-cancelled signal is reduced.