The purpose of this research is to study the effect of rice straw softening treatment time and mixing ratio between rice straw and wood particle on the quality of mixed particle board from Acacia mangium wild wood and rice straw to evaluate whether this technology suit to the technological and production conditions in Vietnam or not. The particle board is amied to make indoor furniture for domestic market. The rice straw was collected in Chuong My district, Hanoi and Acacia mangium wild wood was collected in Ba Vi district, Hanoi. The particle board designed in the experiment is three-layers particle board with the ratio of 1:3:1. The thickness of particle board is 18 mm. The density of particle board is 0.7 g/cm3 with board size of 800 x 800 x 18 mm (including trimming). Resin mixture between commercial urea-formaldehyde (U-F) adhesive from Dynea and methylene diphenyl isocyanate (MDI) adhesive from Casco adhesive company was used with resin dosage of 12 percent for core layer and 14 percent for surface layer. In this experiment design, the input parameters are as follow: softening treatment (steaming) time for rice straw is 15, 30, 45, 60, 75 in minutes at 100°C and rice straw-wood nllxing ratio is 10, 20, 30, 40, 50 in percentage. The results shown that the optimum pressing conditions is that: softening treatment time for rice straw is 46.12 minutes with the strawwood mixing ratio of 29.85 percent. With this pressing condition, the quality of the particle board achieved is as follow: modulus of rupture (MOR) of 14.64 MPa, internal bond (IB) of 0.382 MPa, thickness swelling (TS) of 8.83 percent and board density of 0.7-0.73 g/cm3.