Today, data is exploding. A large amount of data needs to be processed in a timely and an efficient manner. Aggregate signatures are an efficient and secure way to handle large numbers of digital signatures. In an aggregate signature scheme, n signatures on n messages from n users can be combined into a single signature, which can make anyone believes that the n messages were indeed signed by the n corresponding users. In the recent decade, numerous certificateless aggregate signature (CLAS) schemes have been introduced. In most CLAS schemes currently known, the number of hash-to-point operations and the size of signature increase linearly with the number of signers, so they are not suitable for computing restricted devices, such as mobile devices. In this paper, a new CLAS scheme is constructed, which requires only two pairing operations and the signature contains only one point and state information. It is more efficient than the previous ones and suit for the mobile devices.