Based on the analysis of the photocurrent behavior of the Pt sandwiched (Bi(3.7)Nd(0.3))Ti(3)O(12) (BNT) films deposited by sol-gel method, the mechanism of the polarization effect on the photocurrent of Pt sandwiched multi-crystalline ferroelectric films was clarified that, in ferroelectric films irradiated by the extra light, the depolarization field directly gives more contribution to the photocurrent when the polarization aligned under the external poling voltage, while the variation of the top or bottom interface Schottky barriers, because of the presence of the polarization charge near the top or bottom interface, have a indirect and subordinate influence on the photocurrent. (C) 2011 Elsevier B.V. All rights reserved.