MoS2-carbon nanofiber composites were prepared via electrospun technique with ammonium thiomolybdate(VI) and polyvinylpyrrolidone. The effects of thermal pretreatment on the morphology of material were studied. The results demonstrate that the composite nanofiber with pretreatment shows a uniform diameter and lots of small size MoS2 particles inside with porous structure. When the composites was used as counter electrodes in dye-sensitized solar cell, a maximum efficiency of 5.7% has been achieved due to the combination of electrical conductivity and catalysis ability from MoS2-carbon nanofiber composites.