In this paper. the distributions of particle velocity in a gas-solid fluidized bed with branched pipe distributor or circle distributor were measured by using a laser Doppler velocimetry. Our results show that, within a certain range of superficial gas velocity, when using circle distributor, the particle velocity is large and the distribution of the particle velocity is even more compared with the branched pipe distributor. On the basis of the amplitude of tangential movement statistics, the amplitude of tangential movement statistics (AVATMS) decreases with increasing the axial height under the appropriate superficial gas velocity. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved.