The electrical properties of polycrystalline CdZnTe (Zn = 4%) having high resistivity (3.3 x 10(9) Omega cm) were investigated by using the time-of-flight technique. We have found that the average drift mobility of as-deposited polycrystalline CdZnTe samples is 1.21 cm(2)/V s and the electron trapping time is 4.6 mu s. In a comparison of annealed samples at different conditions, the variation of resistivity in polycrystalline CdZnTe is considered to be mainly related to the fluctuation of carrier concentration, which originates from the change of density in deep level. (c) 2006 Elsevier B.V. All rights reserved.