Abstract: The fuzzes weights in Toray T800H and China T800 carbon fiber tows were investigated under friction by rubbing the fiber tows between a pair of sponges and tension along the fiber tows by stretching. Results show that the fuzzes weights of China T800 are much higher than in Toray T800H. The effect of a compressive load on the sponges and a tensile force on the fiber tows on the fuzzes weights is noticeably different for the two tows. SEM images show that the fuzzes weights of China T800 are more than that in Toray T800H. AFM indicates that the sizing of China T800 is less uniform than that of Toray T800H. Moreover, interweaving of the filaments in China T800 is more apparent than in Toray T800H. These three factors contribute jointly to the larger fuzzes weights and its more obvious increase under both friction and tension for the China T800 than the Toray T800H tows.