Transition metal dichalcogenide (TMD) monolayers have recently garnered significant attention owing to their favorable electronic and optoelectronic properties. To date, chemical vapor deposition (CVD) growth of molybdenum di-sulfide, -selenide, and -telluride (MoS2, MoSe2, and MoTe2, respectively), and tungsten di-sulfide, -selenide, and -telluride (WS2, WSe2, and WTe2, respectively) has been widely investigated as the most promising two-dimensional (2D) TMDs. However, scalable and controllable growth of high-quality TMD monolayers remains a challenge. This review highlights the advances of CVD technique by focusing on the aspects of growth promoters, surface energy assistance and site selectivity, which are of great significance for the growth of monolayer TMDs. The challenges for high-performance applications are discussed at the end with a brief outlook on future work.