Nanocrystalline Prl2Fe82B6 and nanocomposite Pr8Fe87B5 ribbons have been prepared using a melt spinning technique. Recoil loops have been measured at 20, 200 and 300K. Demagnetization curves are analysed by dividing it into reversible and irreversible portions. High recoil loop susceptibility at low applied field and large reversible change in the demagnetization curve have been found in Pr8Fe87B5 ribbons, showing that the reversible behaviours in nanocomposite permanent magnets originate primarily from the magnetically soft phase. The hysteresis in recoil loops found in Pr8Fe87B5 ribbons originates from the soft phase α-Fe that suffers a stress.