We propose an identity-based proxy ring signature scheme from bilinear pairings which combines the advantages of proxy signature and of ring signature. Furthermore, our scheme can prevent the original signer form generating the proxy ring signature, thus the profits of the proxy signer are guaranteed. We introduce bilinear pairings to minimize the computation overhead and to improve the related performance of our scheme. As compared with Zhang's scheme, our scheme is a computational efficiency improvement for signature verification because the computational cost of bilinear pairings required is reduced form O(n) to O(1). In addition, the proxy ring signature presented in This work is signer ambiguous, nonforgeable, verifiable, nonrepudiable and identifiable.