An apparatus and method for reducing power consumption of a receiver by performing a Hybrid Automatic Repeat reQuest (HARQ) according to a detected decoding error are provided. The apparatus includes a decoding reliability metric generator for setting a decoding result as a decoding reliability metric, which is a reference value for determining a code block having a decoding error, based on a decoding result, a decoding reliability metric buffer for storing the decoding reliability metric set by the decoding reliability metric generator and a code block controller for, when the decoding error occurs, identifying code blocks having the decoding error by checking the decoding reliability metric and for controlling to decode the identified code blocks.