AC(3)B(4)O(12)-type perovskite CaCu3Ti4O12 (CCTO), square 0.34Pr0.67Cu3Ti4O12 (PCTO), square 1Cu3Ta2Ti2O12 (CTTO), square 2Cu2Ta4O12 (CTO) ceramics with different concentration cation vacancies were prepared through traditional solid state reaction method. X-ray diffraction analysis indicated that CCTO and PCTO are perovskite cubic with space group Im-3 (no. 204) while CTTO and CTO are Pm-3 (no. 200). Cell parameter of the samples dramatically increases with the increase of cation vacancies. Dielectric permittivity of them maintains very high value of similar to 10(4) from room temperature to 550K but the dielectric loss is depressed with the increase of cation vacancies in the same space group. The dielectric properties and conductivity behavior were described by the Debye relaxation and the universal dielectric response, respectively. The effect mechanism of cation vacancy and crystal structure on carrier transposition were discussed. (C) 2015 Elsevier Ltd. All rights reserved.