An apparatus for recovering high speed NRZ (non-return to zero) data is disclosed. A phase-locked loop (PLL) frequency-divides the frequency which is outputted from a voltage-controlled ring oscillator, and therefore, the physical limit of the PLL is not affected. The voltage-controlled ring oscillators are installed separately from the PLL, and the voltage-controlled ring oscillators are synchronized with the PLL in the frequency only. Further, the oscillators are phase-locked to the incoming NRZ data, and two voltage-controlled ring oscillators are enabled/disabled by the binary values of the NRZ data. Therefore, a bit synchronization is realized, and thus, the voltage-controlled ring oscillators are directly controlled by the NRZ data. Consequently, the NRZ data can be recovered up to the frequency band at which the voltage-controlled ring oscillators and a D flip flop operate.