Abstract:The model of finite length carbon nanoscrolls are constructed from rolling graphene sheets. Based on the tight-binding approach in the energy-band theory, an analytical relation between dispersion relation, chirality, structural parameters and length is derived and analyzed. The relation immediately suggests that with different geometric structures, there arise metal-semiconductor transition and distinct asymptotic band-gap behaviors as a function of length: damped oscillations decaying, monotonic decay, and constant.