High-density three-dimensional Mo2S3 flowers have been facilely synthesized with controlled sites by introducing gold particles as the nucleation sites in a chemical vapor deposition process. The whole size of each flower is in micro scale while individual petal has extremely small thickness of around 10 nm. The role of gold particles and precursor concentration in the growth has been carefully investigated. Without gold particles, dense nanopetals were not able to be obtained unless in a highly concentrated sulfur atmosphere. With Au particles, dense products were steadily achieved in a wide precursor concentration range with S:MoO3 molar ratio from 1:5 to 5:1. The morphology and structure of the as-synthesized nanostructures were characterized using field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HRTEM). The growth mechanism was proposed in which gold particles acted as the initial nucleation sites fixing the nucleation position of the flowers following vapor-solid growth mechanism. (C) 2012 Elsevier B. V. All rights reserved.