Abstract: This paper proposes a parallel image encryption algorithm based on chaotic and bit level permutation (CBLP). The CBLP algorithm includes the pixel position permutation operation, bit rotation and XOR operation, and therefore the image is confused by the pixel position permutation and diffused by the bit rotation and XOR operation. In order to take full advantage of the heterogeneous processing platform to enhance the efficiency of the algorithm substantially, an OpenCL-based implementation of the algorithm with NVIDIA's GeForce GTX 580 GPU device has been shown in this paper. Comparing to the implementation on CPU, the CBLP algorithm has the high encryption efficiency and the high security, and can be used effectively in practical encryption operation.