Dynamic light scattering has been measured on aqueous solutions of a nonionic surfactant C14E6 (C&E,,, represents a chemical formula CnHz~+l(OCzH&OH ). In t&e time correlation function of the scattered field for semidilute solutions where wormlike micelles are entaii&ed, we have found the so-called slow mode in addition to the diffusion mode. Concentration and temperature dependences of the relaxation time of the slow mode (rs) are strongly correlated with those of the surfactant self-diffusion coefficient (D), suggesting that self-diffusion and structural relaxation are dominated by the same kinetic process. These results are consistent with our previous study on the &ET system. In order to refine the kinetic model, we have compared G and D quantitatively based on our diffusion model reported before where intramicellar diffusion and intermicellar migration are taken into account. Static light scattering measurements have been performed to estimate one of parameters included in this model. It has been suggested that entangled micelles form a transient connection whose lifetime is of the order of 10-S s, depending on concentration and temperature, and that surfactant molecules migrate to another micelle through such a transient connection.