Bare nanoparticles synthesized by laser ablation in water have found their application in, catalysis, spectroscopy and biomedical research fields. In this perspective, how to efficiently produce stable nanoparticles with controllable size is an important topic and has attracted a lot of interests. Here, we introduce a multiple-pulse laser as the ablation source. By changing the number of sub-pulses, the average size of nanoparticles can be tuned in a broad range from similar to 120 nm to similar to 4nm. The demonstration in this article may offer a new approach to fabricate ultrafine nanostructures and also help the scientific study of the mechanism in laser ablation. (C) 2017 Elsevier B.V. All rights reserved.