Positron annihilation measurements as a function of temperature and time have been carried out on a poly(butadiene). The measurements were performed at several temperature points from 14 to 225 K. The measurement time was several hours to four days. The analysis of data shows the following features:(i) the value of τ 3 does not depend on the rate of cooling or time,(ii) the value of I 3 depends on the rate of cooling and the history of thermal treatment,(iii) the dependence of I 3 on time can be described by Debye function. But the rise in I 3 is observed at very low temperatures,(iv) the I 3 decays to value of I 3 observed during very slow cooling.