This paper presents a charge-based compact model for predicting the current-voltage and capacitance-voltage characteristics of heavily doped long-channel cylindrical surrounding-gate (SRG) MOSFETs. Starting from Poisson's equation with fixed charge and inversion charge terms, a closed-form equation of inversion charge is obtained with the full-depletion approximation. Substituting this inversion charge expression into Pao-Sah's dual integral. a drain current expression with concise form is derived. Based on the Ward-Dutton linear-charge-partition method and the current continuity principle, all trans-capacitances are obtained analytically. The developed model is valid in all operation regions from the subthreshold to strong inversion and from the linear to the saturation region without any smooth function. The model predictions have been extensively compared with 3D numerical simulations and a good agreement is observed in most of the operation regions with a wide range of geometrical parameters. (C) 2008 Elsevier Ltd. All rights reserved.