Discrete cosine transform is an ideal method to decorrelate the signal. In this paper, we proposed a novel entropy coding based on 1D-DCT to compress the 3D point clouds. Different from the former method which is based on Laplacian distribution, we encoding the coefficients by count the nonzero coefficients. We count the number, index, value of the nonzero coefficients of each block and then use arithmetic encoder to compress the coefficient. Experimental results on a number of point clouds show our method is more efficient than the former method based on DCT.