The poly (lactic acid) (PLA)/ rice straw (RS) composites with various RS content ratios were prepared by using heated two roll-mill. The mechanical performances of prepared PLA/ RS composites were studied. The tensile strength and elongation at break, Eb of the composite decreases as the content of rice straw fiber increases from 5% to 25% while the Young’s modulus had increases. Fourier transform infrared (FTIR) analysis demonstrates the infrared absorption of PLA after the existing of RS.