A method of indicating a downlink (DL) control channel for a network of a wireless communication system method comprises configuring an enhanced physical control format indicator channel (ePCFICH) according to an amount of resource for transmitting an enhanced physical DL control channel (ePDCCH) of a subframe, wherein the ePDCCH is dedicate to a communication device of the wireless communication system or to a group to which the communication device belongs; and transmitting the ePCFICH to the communication device via a plurality of bits of a physical hybrid automatic repeat request (HARQ) indicator channel (PHICH) of the subframe, to indicate the amount of resource for transmitting the ePDCCH to the communication device.