The line change-over circuit suitable for the semiconductor memory having a redundancy memory column comprises a pair of transfer gate elements provided between a first node to which a first signal to be transmitted is supplied and a pair of transmission lines, first and second switch elements. The paired transfer gate elements are controlled on a switch in complementary manner each other according to a transfer signal. The first switch element is controlled on a switch according to the transfer signal, and the second switch element is controlled on a switch according to the first signal transmitted to one of the paired transmission lines. The first switch element turns one of the transmission lines to a fixed potential like ground potential when it is kept on, and the second switch element turns the other of the transmission lines to a fixed potential when it is kept on. The line change-over circuit in the above configuration is effective to prevent a floating state of the paired transmission lines.