A phase servo circuit for controlling a rotatable magnetic head which is used for recording and/or reproducing a television signal includes a pulse generator for producing a pulse signal synchronous with the rotating phase of the rotatable magnetic head, a phase difference detecting circuit for generating a control signal which is used for controlling the rotating phase of the rotatable magnetic head, the control signal having a pulse width modulated in response to the phase difference between the pulse signal and the vertical synchronizing signal of a television signal to be recorded, another circuit for detecting the phase difference between the aforementioned vertical synchronizing signal and a second vertical synchronizing signal of a reproduced television signal and a modulating circuit for modulating the pulse width of the control signal in response to the output of the phase difference detecting circuit, whereby the phase angle of the first-mentioned and second vertical synchronizing signals are in synchronization with each other on a magnetic tape in order to carry out tape editing operation.