Abstract: Rice straw and wood based medium density fiberboards (MDF) were made in the lab. Three kinds of mixed methods for manufacturing straw and wood based MDF in this research were as flowers: Firstly, raw material of rice straw and wood were mixed, then were made to be fibers with urea-formaldehyde sprayed. Secondly, rice straw and wood raw material were made to be relevant fibers, then mixed with UF sprayed. Finally, rice straw and " wood raw material were made to be relevant fibers, then UF was spayed and mixed. Wood to rice-straw ratio in this research was 0, 10%, 20%, 30%, 40%, 50%, and 100%, respectively. The content of water repellent was 0.8%, 1.2%, 1.6%, and 2. 0%, respectively. Results showed that with 50% wood fiber, 1.20/00 water repellent, and 12% UF, all physical and mechanical properties of straw and wood based MDF could reach to the standard values of GB except for thickness swell.