Nano tin oxide (SnO2) was synthesized by a novel, fast and facile approach through applying electric current of high density to a line-type joint specimen consisting of a high tin-content alloy between two pieces of conductor (copper or nickel). The fabricated SnO2 shows various morphologies, such as branch-like, pine-leaf-like, grass-like and batting-like, and has the tetragonal rutile structure confirmed by scanning electron microscopy, energy dispersive X-ray spectroscope and Raman spectrum. The present work has not only offered a facile and novel method for fabricating SnO2 of various morphologies, but also provided an inspiriting yet practical idea as well as technical possibilities for preparation of other functional oxide materials.