Carbon fiber-reinforced Si-C-N matrix composite with a Si-O-C interlayer (C/Si-O-C/Si-C-N) was fabricated via chemical vapor infiltration and polymer impregnation and pyrolysis processes. The oxidation behaviors of C/Si-O-C/Si-C-N were investigated in air by comparing with that of C/Si-C-N using thermogravimetry and SEM techniques. The results indicate that the weight loss of the C/Si-O-C/Si-C-N increases with the increase in the temperature below 800 degrees C, decreases in the range of 800-1000 degrees C, and increases again above 1000 degrees C. The oxidation resistance of C/Si-O-C/Si-C-N was improved greatly as compared to C/Si-C-N within the temperature range from 600 to 1200 degrees C. The higher oxidation resistance of C/Si-O-C/Si-C-N results from the low density of crack, weak interfacial bond of Si-O-C interphase/matrix, and tight interfacial bond of interphase/carbon fiber. The weak interfacial bond between Si-O-C interphase is the main reason for improvement of oxidation resistance of C/Si-O-C/Si-C-N.