To push energy and power limits of aqueous pseudocapacitors, advanced anode materials are highly desirable. In this work, pyrite FeS2 nanobelts are fabricated through a soft-template-assisted one-pot method. The high electrical conductivity and nanostructured morphology of this anode material facilitate charge transports, thus considerably improving pseudocapacitive performance compared to Fe2O3 and FeS2 contrast samples. This material can deliver a high capacitance of 308.3Fg−1/317.8Fg−1 at 5mVs−1/3Ag−1. It also exhibits good rate capability that 64.2% and 42.0% of the above capacitance can be retained when the scan rate and current density are increased to 10-fold, respectively, and superior long-term cyclability that 81.1% capacitance retention can be obtained after 1000 cycles. The results demonstrate great potential of pyrite FeS2 anode material for aqueous pseudocapacitors.