A co-prime compressive sampling scheme based on chaotic digital filter is proposed. Compressive measurement matrix that employing chaotic digital filter avoid the problem of hardware implementation of classical Gaussian random measurement matrix. It also reduce the complexity of subsampling hardware implementation, while ensuring the incoherence of sensing matrix. For further reduction of data to be processed, a coprime sampling method is devised for compressive sensing radar. Numerical results demonstrate that compressive radar system that using the proposed coprime chaotic compressive sampling scheme can detect target’s parameters accurately.