The A and B forms of NaDNA with hydration level of between 0.15 and 0.64 (g of water)/(g of NaDNA) have been vitrified by cooling at rates between 4 and similar to 2700 K min(-1), and their thermal behavior on reheating was studied from similar to 120 to 300 K by differential scanning calorimetry (DSC). The effects of the annealing time, t(a), for two different hydration levels at a fixed temperature and of the annealing temperature, T-a, for a fitted t(a) have been investigated, and the effects of various T-a and t(a) on the enthalpy and entropy relaxations and recovery were ascertained. From these effects we evaluate tau(a), the characteristic structural relaxation time, E*, the activation energy, tau(0), the preexponential factor, and beta < 1 as an empirical parameter for apparent distribution of relaxation times. No DSC features of significance that may be attributed to the onset of molecular motions are found for A-DNA or when the water content is low, but for B-DNA and high water content, endothermic features resembling the onset of molecular motions, or glass --> liquid transition, are observed from similar to 153 K to similar to 263 K.