Monolayer semiconductors of molybdenum disulfide (MoS2) crystals have drawn tremendous attention due to their extraordinary electronic and optical properties. A uniform and high-quality crystalline MoS2 monolayer is greatly needed in fundamental studies and practical applications. Three-point star to six-point star MoS2 nanosheets are readily synthesized in a controlled manner using the chemical vapor deposition method. A possible coalescent model is proposed to study the evolution of the six-point star MoS2 domain. A comparative study of field effect transistors are performed to disclose the negative effect of grain boundaries on the transport properties based on six-point star MoS2.