Provided are a method and an apparatus for converting an interface between high speed data having various capacities. The apparatus includes a data transmitting part and a data receiving part. The data transmitting part generates a deskew channel having respective timing data of a plurality of data transmitted from a first communicating device, and outputs the generated deskew channel together with the plurality of data to a second communicating device. The data receiving part compares the deskew channel transmitted from the second communicating device with the plurality of data to measure skew values of the data, aligns bits and bytes of the plurality of data using the skew values, and transmits the plurality of data to the first communicating device.