Our study demonstrates that the C(69)N azafullerene can be encapsulated inside single-walled carbon nanotubes (SWNTs), which is confirmed by TEM, UV-vis-IR spectroscopy, Raman spectroscopy, and UPS. The electrical transport properties of SWNTs are found to change drastically due to the encapsulated C(69)N azafullerene. Our experimental results indicate that C(69)N encapsulated SWNTs show the high-performance n-type behavior compared with p-type characteristics of pristine SWNTs and C(70) encapsulated SWNTs. This n-type transport characteristic can be explained by the charge transfer effect between SWNTs and encapsulated C(69)N, which can easily lose an electron. The unique electronic properties of C(69)N encapsulated SWNTs make them potentially useful in many applications in engineering functional nanodevices.