MXenes, two-dimensional (2D) layered early transition metal carbide, nitride and carbonitride materials, have been prepared by exfoliating MAX phases. In addition to 2D planar MXene, one-dimensional tubular forms are also expected to form. Herein, we design atomic models for Sc sub(2)C monolayers and nanotubes as well as their functionalized counterparts, and investigate their stability and electronic properties through the density functional theory tight-binding method. Dramatic distortion of Sc sub(2)C and Sc sub(2)CO sub(2) tubular structures occurs, while Sc sub(2)CH sub(2) and Sc sub(2)C(OH) sub(2) nanotubes preserve their tubular morphology upon structural relaxation. Moreover, we reveal that the radii of nanotubes play an important role in the relative stability and band gaps of tubular forms. Sc sub(2)CH sub(2) and Sc sub(2)C(OH) sub(2) nanotubes are direct-band-gap semiconductors, while the electronic structure of their corresponding planar forms depends on the arrangement of the functional groups.