Ring signature is an anonymous authentication that authenticates the message while protecting the identity of the authentic signer. It is suitable for many scenarios, such as electronic voting, anonymous access control, etc. Most certificateless ring signature schemes currently known used bilinear pairings. The computation cost of the pairings is much higher than that of the scalar multiplication over the elliptic curve group. Therefore, it is quite significant to design certificateless ring signature without pairing. In this paper, we constructed a new certificateless ring signature scheme and prove it to be secure in the random oracle model, under the assumption that it is hard to solve the discrete logarithm (DL) problem on elliptic curve group. Our scheme does not use pairing operation, taken into account the computation costs for signing and verifying, it is more efficient than all the certificateless ring signature schemes currently known.