Abstract: In order to investigate the mechanical breaking properties of brown rices and their relationships with its kernel structure, texture analyzer tests were used to determine and analyze the stabbing forces, three-point bending, anti-shearing and compressing forces of brown rices. Breaking properties (three-point bending) of brown rices and milled rices were compared. The results showed that the occurrence of crush was due to the uneven of the endosperm and in the external force, the internal cracks were formed firstly, and stress concentration at the crack tip promoted further crack propagation, which led to grain fracture eventually. Stabbing breaking force of different samples with thickness of (1.0±0.5) mm were about 10 N, and the binding force of different samples were closed, and the crush in the grain processing was related with thickness and endosperm properties of the grain. Three point bending force better reflected the broken properties of grain in the process of milling. Under the protect of bran layer, the mechanical properties of brown rices were better than the milled rices. The results provide a base for the determination of the brown rice processing and storage technique.