The oxidation behavior of SiC whiskers (SiCW) with a diameter size of 50-200nm has been investigated at 600 degrees C-1400 degrees C in air. Experimental results reveal that SiCW exhibit a low oxidation rate below 1100 degrees C while a significant larger oxidation rate after that. This can be attributed to the small diameter size of SiCW, which determines that it is hard to form a protective SiO2 layer thick enough to hamper the diffusion of oxygen effectively. Both nonisothermal and isothermal oxidation kinetics were studied and the apparent oxidation energy was calculated to further understand the oxidation behavior of the SiCW.