Abstract. Stirred media mills are invoked as high energy utilization equipment to prepare superfine particles with a narrow particle size distribution. In this study, the effects of the stirrer tip speed and the grinding media diameter on the particle size distribution of lotus leaf powder (LLP) were investigated. The stress intensity and stress number, which were determined by the stirrer tip speed and grinding media diameter, were applied to estimate the wet grinding kinetics of LLP. The stress conditions with the minimum specific energy consumption were a grinding media diameter of 1.4 mm and stirrer tip speed of 8.4 m s-1. Additionally, FT-IR measurements of the samples confirmed that the chemical structures of the active ingredients were not damaged with reduction in particle size, which indicated the mildness of the grinding process.HighlightsA stirred media mill was initially applied for preparing superfine lotus leaf powder.The stress conditions with the minimum specific energy consumption were determined.The active ingredients were not denatured during the grinding process. Keywords: Grinding kinetics, Lotus leaf, Stirred media mill, Stress intensity.