A connection structure for connecting a differential signal transmission cable to a circuit board. A differential signal transmission cable includes an outer conductor provided around a pair of signal line conductors via an insulator. Parts of the signal line conductors are exposed from a tip of the differential signal transmission cable. A circuit board is provided with a pair of signal pads and a ground pad. A shield-connecting terminal includes a main body which is crimp-connected to the outer conductor and a solder-connecting pin which is solder-connected to the ground pad. The exposed parts of the signal line conductors are solder-connected to the signal pads, respectively, and the outer conductor is solder-connected to the ground pad via the solder-connecting pin of the shield-connecting terminal.