Molybdenum disulfide (MoS2) has been considered as a promising anode material for sodium-ion batteries. But the low electronic conductivity and large volume change during sodiation/desodiation processes limit its wide application. In the present study, a single-layer MoS2 embedded in amorphous carbon nanofibers is fabricated by electrospinning. The obtained MoS2/carbon nanofibers have unique hierarchical structure incorporating 2D single-layer ultrasmall MoS2, 1D carbon continuous phase and 3D interconnected porous network. When employed as anode material in sodium-ion battery, this hierarchical structure can enlarge accessible surface area of MoS2, accelerate ion diffusion speed, shorten ion transfer length and improve the bulk conductivity, and then endow MoS2/carbon nanofibers composite with high capacity and superior cycling stability. The electrochemical results show that the initial discharge and charge capacities of MoS2/carbon nanofibers can reach 921 and 665 mAh g(-1). After repeated charge-discharge test for 100 cycles, a stable capacity of 485 mAh g(-1) is achieved, demonstrating a very low capacity loss of 0.05% per cycle.