A simple calcination method was explored to synthesise the tremella-like molybdenum disulphide (MoS 2), Mo trioxide (MoO 3)/MoS 2 and MoO 3 nanoplates by using the pristine MoS 2 nanosheets as the precursor. The possible formation and growth mechanism from the pristine MoS 2 to the tremella-like MoS 2 , MoO 3 /MoS 2 nanoplates and MoO 3 nanoplates was proposed. It was found that the calcination temperature was a key factor for the formation, ingredient and phase structure of the three samples. The adsorption properties of the three samples for an aqueous solution of methylene blue (MB) at room temperature were investigated. The results revealed that the products exhibit the better adsorption capacities with increasing the ingredient of MoO 3 in the transformation process from MoS 2 to MoO 3. Therefore, the pure MoO 3 nanoplates have the highest adsorption and removal rates, which reached 96.9% at MB concentration of 10 mg/l and 90.9% at MB concentration of 20 mg/l.