Most thermoplastic fibrous materials have low dielectric constant enabling direct bonding of the composing fibers by microwave heating. However, the bonding capability between nanofibers can be highly increased by blending additives having high dielectric constant. In this paper, nylon 66 nanofibers were produced with the carbon black particles, which have high permittivity, by the electrospinning method. The produced carbon black/nylon 66(CB/N) hybrid nanofiber webs of different carbon black contents were heated by the microwave system for different treatment times. The morphological structure and strength properties of CB/N hybrid nanofiber webs were investigated to verify their bonding behavior. The results showed that the bonding strength of pure nylon 66 nanofiber webs prepared by microwave heating was weak, but the bonding area at the contact point of nanofibers having carbon black increased with increasing microwave treatment tine. In spite of increasing bonding area, the bonding strength of CB/N nanofiber webs does not increase due to the decrease in fiber diameter.