Flower-like ZnO microstructures were successfully produced using a hydrothermal method employing ZnSO4/(NH4)2SO4 as a raw material. The effect of the operating parameters of the hydrothermal temperature, OH-/Zn2+ molar ratio, time, and amount of dispersant on the phase structure and micromorphology of the ZnO particles were investigated. The synthesis conditions of the flower-like ZnO microstructures were: hydrothermal temperature of 160℃, OH-/Zn2+ molar ratio of 5:1, reaction time of 4 h, and 4 mL of dispersant. The flower-like ZnO mi-crostructures were comprised of hexagon-shaped ZnO rods arranged in a radiatively. Degradation experiments of Rhodamine B with the flower-like ZnO microstructures demonstrated a degradation efficiency of 97.6％ after 4 h of exposure to sunshine, indicating excellent pho-tocatalytic capacity. The growth mechanism of the flower-like ZnO microstructures was presented.