The dynamical properties of stripes in high T-c oxide superconductors are studied theoretically at finite temperature (T) within RPA scheme on the two-dimensional Hubbard model. It is found that at lower dopings, the transverse dynamical susceptibility in the antiferromagnetic state exhibits the anomalous broadening of the spin wave spectral line width upon lowering T, indicating a phase transition to an incommensurate state. At a higher doping, the detailed T-evolutions of the spin wave spectrum are studied. (C) 2002 Elsevier Science Ltd. All rights reserved.