Abstract: In order to utilize plant fibers of crops and agricultural wastes, and to research on environmental friendly material, four kinds of plant fiber powder/ polypropylene composites were prepared. The tensile strength, blexural strength and blexural modulus of the composites were evaluated, and the water absorption and pyrocondensation of the materials were investigated. The results showed that the polypropylene composite filled with straw and rice husk hybrid powder had good mechanical properties, tensile strength and flexural strength of the composites filled with rice husk powder or wood powder or straw and rice husk hybrid powder had little difference. Bamboo powder/polypropylene composites had poor performance, low mechanical properties, and large water absorption and heating rate of change. Rice husk powder and polypropylene composites had better consistency, and bamboo or wood powder was compatible poorly with the polypropylene. The properties of composites decreased, and the composites had brittle destruction. Rice husk powder, mixed powder of rice husk and straw, and polypropylene can be made for the wood-plastic composite material with better properties.