Within the framework of first‐order kinetics the activation energy spectrump(U) for thermal activated flux motion in YBa2Cu3O7−&dgr;single crystals is derived from the time decay of the magnetic polarization &mgr;0M(t). The distribution functionp(U) turns out to be temperature independent, so that the time dependence of &mgr;0M(t,T) can be described by one unique spectrump(U) in the whole temperature range 0 <T<Tc. Concerning the crystal directionsH∥cˆandH⊥cˆ, respectively, a threshold energy in the caseH⊥cˆis noticed which may be related to the Peierls potential, formed by the Cu‐O planes.