This paper proposes a novel image encryption scheme based on DNA sequence operations and chaotic system. Firstly, two-dimensional logistic chaotic map is employed to modify each pixel of the image, and then, the DNA encoding rules are adopted to encode and generate a DNA matrix. Secondly, pseudo-random sequences generated by twodimensional logistic map are transformed into another DNA matrix. Thirdly, DNA addition, subtraction and complementary rules are used to control the operations between two DNA matrices for obtaining the ciphered results. Finally, the ciphered image is obtained by decoding the DNA matrix formulations into binary formulations. Experimental results and theoretical analysis show that the scheme is extraordinarily high secure to resist various attacks.