Abstract: A composite laminate with bonded piezoelectric film as sensor under uniaxilstretching is analyzed by means of modified quasi threed-dimensional finite element method.The influence of piezoelectric layer on interlaminar stresses is discussed and then the voltagedistribution on piezoelectric sensor is obtained in the presence of delamination. The resultsshow that it is feasible to detect the delamination by use of piezoelectric sensor. Finally,various affecting factors are discussed.