Recently, Li-ion capacitor as a kind of novel energy storage device with high energy density and power density have caused wide concern. In this study, the porous carbon nanofiber/molybdenum disulfide nanoflake-flowerballs composite material is successfully prepared via hydrothermal method using the three-dimensional porous carbon nanofibers as a carrier. The molybdenum disulfide nanoflake-flowerballs are uniformly distributed and fill in three-dimensional porous carbon nanofibers skeleton, and the clear composite material with nanofiber morphology is formed. This material presents moderate specific surface area (81.67 m(2) g(-1)) and good electrical conductivity (22.32 S cm(-1)) and is used as the anode in the Li-ion capacitor, and the big energy density at high power density (the energy density could reach 75.5 Wh kg(-1) and 22.5 Wh kg(-1) at power densities of 0.075 kW kg(-1) at 30 kW kg(-1), respectively) are achieved, which has broad application prospect in the energy storage field.