Abstract: The paper focuses on the wafering of straw in openend die. A series of experiments are conducted on a hydraulic driven piston wafering machine to find the effects of main processing factors on the properties of wafer. The results show that wafers produced from straw with 15％ moisture are of higher density and durability，relaxation ratio decreases with the increase of charge at a given diameter，wafers made of longer straw are more durable. Relationships between pressure and density，durability and relaxed density，and specific energy and relaxed density are determined through analysis of experimental data. The experimental study on staw wafering and its results lay an important base for designing of straw wafering machine with openend die and wafer production.