A hydrothermal process without using any surfactants or templates has been employed to prepare SrSO 4 microrods with different crystallographic morphologies. The pH value of the reaction solution is determined to be the key factor in the formation of rod-like morphology. It is found that the length-to-diameter ratio (L/D) of the rod-like SrSO 4 crystals increases from 1 to 4 when the pH value increases from 3 to 12. Besides, the effects of hydrothermal reaction time and temperature have been investigated to illustrate the morphological evolution process of SrSO 4 crystals, and it is also discussed that the microcrystals formation mechanism of the evolution process.