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Nanoscrolls, radial superlattices formed by rolling up two-dimensional nanomembranes, exhibit electronic and magnetotransport properties distinct from those of their flat counterparts. Using theoretical modeling, we predict that carbon nanoscrolls host topological valley states that give rise to a remarkable positive magnetoconductance under a longitudinal magnetic field [1,2]. We further predict that the conductance can be precisely enhanced N times by rolling up graphene into an N-turn nanoscroll and applying a longitudinal magnetic field. This tunable positive magnetoconductance stems from the topological winding number which is activated in a carbon nanoscroll with magnetic flux and its maximum value purely increases with the scroll winding number (the number of turns) [3,4]. By combining material geometry and topology, carbon nanoscrolls offer a versatile platform for creating, tailoring, and designing topological quantum states in rolled-up graphene-based materials.