The local chain dynamics of poly(oxyethylene) (POE) labeled with anthryl group in the middle of the main chain was examined by the fluorescence depolarization method. The relaxation time of the local motion was evaluated and its molecular weight dependence was shown. POE had a mean relaxation time in the order of subnanoseconds. The value of the relaxation time increased with the molecular weight in the range of MW < 4000 and reached an asymptotic value at MW of about 4000. The relaxation time and the activation energy for local motion of POE were compared with those of some styrene and methacrylate polymers and the characteristics of POE chain were discussed. POE had a much higher local chain mobility than other polymers. This high local chain mobility of POE results from the molecular structure of POE chain.