An apparatus for correcting a time base of a video signal generates a clock which is phase-synchronized with a sync. signal of the video signal and has the same frequency. In a special reproducing mode, the apparatus switches an output level of a phase comparator, which phase-compares the sync. signal and the clock to a predetermined level, which is applied to a controlled oscillator and resets a frequency divider which frequency-divides the output of the controlled oscillator, in accordance with the sync. signal to produce the video signal which can be visually recognized even in the special reproducing mode. The apparatus samples and holds the output level of the phase comparator when the video signal drops out and resets the frequency divider which produces the clock by frequency-dividing the output of the controlled oscillator, when the dropout is recovered so that a video signal of high quality is produced immediately after the recovery of the dropout of the video signal.