Self-powered wearable devices are gaining increasing attention to fulfil the sensing and energy harvesting needs for the next-generation wearable systems and body sensor networks. Here, we developed a wearable, flexible and lightweight nanofiber-based triboelectric nanogenearator (NF-TENG) for body motion energy harvesting. Polyvinylidene difluoride (PVDF) and nylon were electrospun into nanofiber films to form the two triboelectric materials. Under a load force of 10 N, the NF-TENG could generate an output voltage of 140 V, current of 0.5 μA and transferred charges of 50 nC. Preliminary body energy harvesting applications of the proposed NF-TENG were demonstrated, wherein the NF-TENG was able to generate an output voltage of 8 V and 10 V during typing and elbow bending, respectively.