A synchronizing signal discrimination circuit for use in a channel selection apparatus having a preset function of a television receiver is disclosed. The circuit has a function to discriminate a periodic and continuous signal and a non-periodic and one-shot signal to distinguish a synchronizing signal from a noise. The present synchronizing signal discrimination circuit determines a time period from the application of a first input signal to the input terminal to the application of a second input signal to the input terminal by the first time interval signal and the second time interval signal to detect only the periodic and continuous signal as the synchronizing signal.