The general behavior of the domain structure in Nd2 Fe14 B as a function of temperature has been reported in an earlier paper [Y. Luo, N. Zhang, and X. Su, Acta Metall. Sin. 23, A136 (1987)]. In order to clarify some details of the temperature variation of domain structure in the basal plane of this material, we have now made observations on a single-phase sample of Nd2 Fe14 B. We find that the optical contrast between antiparallel domains, using the Kerr effect for observation, is approximately proportional to the saturation magnetization; both decrease with increasing temperature. The main basal-plane domains are unchanged by heating, but the supplementary closure domains (cone-shaped reversal domains) change in size and shape, and may even disappear, when the sample is heated above 240 °C. Since the domain nucleation process is to some extent random, the domain pattern is different after each thermal demagnetization cycle above the Curie temperature.