A circuit layout structure is provided. In the circuit layout structure, a transmission line group is disposed on a substrate. In its first differential signal transmission line pair, a first negative polarity transmission line is parallel to a first positive polarity transmission line and is configured to transmit a first negative polarity transmission signal of a first differential signal. In a second differential signal transmission line pair, a second positive polarity transmission line is parallel to a single-ended signal transmission line and is configured to transmit a second positive polarity transmission signal of a second differential signal. The second negative polarity transmission line is parallel to the second positive polarity transmission line. The single-ended signal transmission line is disposed between the first differential signal transmission line pair and the second differential signal transmission line pair.