We observed the regular morphology evolution of chemical vapor deposition (CVD) grown MoS2 nanorods along the gas flow direction on the SiO2/Si substrate. It can be attributed to the concentration gradient of the gas phase MoO3 along the gas flow direction, which impacts the average growing rate of the MoS2 crystals. The MoS2 domains experience a regular morphology transformation as well as a size change as the deposition location moves closer to the MoO3 powder. It paves the way for the development of CVD method with controlled growth parameters and opens up new venues for the tunable morphology evolution of MoS2 nanorods. (C) 2015 Elsevier B.V. All rights reserved.