Single-crystalline LiV3O8 nanobelts have been synthesized by using V2O5 nanobelts as the vanadium resource via a facile solid-state reaction method. The LiV3O8 nanobelts with thickness of less than 20 nm, widths of 100–300 nm, and length up to several micrometers can grow along the  direction. The small thickness of LiV3O8 nanobelts are expected to shorten the Li+ ion diffusion distance for the improved electrochemical performance of electrode material. The influence of types of lithium salts on the morphologies and sizes of LiV3O8 nanostructures has been investigated. When used as the cathode material in rechargeable lithium batteries, LiV3O8 nanobelts exhibit stable lithium-ion intercalation/deintercalation reversibility and deliver initial specific discharge capacities of around 356.2 mAh/g at 0.02 A/g, 273.6 mAh/g at 0.05 A/g, and 234.0 mAh/g at 0.1 A/g, respectively. After 30 cycles, the specific discharge capacities are lowered to 298.6 mAh/g at 0.02 A/g, 234.5 mAh/g at 0.05 A/g, and 195.5 mAh/g at 0.1 A/g, respectively. The good electrochemical properties of LiV3O8 nanobelts make them a promising candidate as a cathode material for rechargeable lithium batteries.