A novel image forensic method based on generalized coefficient-pair histogram in DCT domain was proposed.In the proposed method,firstly,the image is transformed by DCT,and then the differential DCT coefficient matrix of two directions,such as horizontal and vertical direction are computed,the following is to compute the coefficient-pair histogram for each differential DCT coefficient matrix within the given threshold.Finally,support vector machine(SVM)is used to classify the authentic and spliced image through training the feature vectors of authentic and tampered image.The experimental results show that the proposed approach has not only the lower computing complexity; it also outperforms all the state-of-the-art methods in detection rate with the same test database.