Rice-hull powder is widely used in manufacturing reinforced plastic composites. However,its weathering ability is rarely considered. We studied the performance of two types of rice-hull-polyethylene (RH-PE) composites after they were exposed outdoor to natural weathering for two years. The samples did not change in bending strength and elasticity modulus. At the end of the testing period,colour lightness had increased by more than 23% and total colour had changed by more than 9 units. This means the colour evidently differentiate from the original colour that the customers choose. The analyses of Fourier-transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) showed that oxidation had occurred on sample surfaces. Red lumber presented an obvious C=O peak after weathering,while yellow lumber did not present an obvious peak as evidence of oxidation. Both types of lumbers showed a reduction of lignocellulosic groups and amorphous regions of PE.