In this paper, the rice husk ash/natural rubber composite was fabricated from the rice husk ash modified using rare earth coupling agent DN-8102. The structure of rice husk ash, the morphological dispersion of rice husk ash in rubber matrix and the mechanical properties of the composites were analyzed. The FTIR results showed that absorption peaks of modified rice husk ash receded significantly at 3200cm-1 and 1705cm-1, at the same time, absorption peak in 2962cm-1, 2927 cm-1 and 1466cm-1 appeared corresponding to rare-earth coupling agent DN-8102. The modified rice husk ash showed good water dispersibility. Particles of rice husk ash dispersed in natural rubber uniformly due to the forming a good interface combined with rubber phase, which increased Van der Waals force between rubber hydrocarbon molecules and molecular chain. The rice husk ash/natural rubber composite possessed significantly higher strength and better thermal stability. The tensile strength of the composite reached to 25.96 MPa when modified rice husk ash filling quantity of 4%, while heat temperature at about 7 ℃.