A channel alignment circuit which is capable of separating six frame signals of 51.84 Mbps (Mega Bit Per Second) for six channels by expanding a control signal from a channel alignment block into three signals for a reframer of a cable television system. The circuit includes a CIB detector for detecting 51.84 Mbps of six descrambled channels and generating a 12-bit channel number data, a control signal generator for generating a 3-bit channel alignment control signal by using a 3-bit data among the channel number data from the CIB detector, and a channel alignment unit for separating the data inputted into six channels in accordance with a control signal from the control signal generator.