Rod shaped carbon nanofibers with 1wt%, 3wt% and 5wt% of iron catalyst loadings are developed by Chemical Vapour Deposition (CVD) and the morphology of the carbon nanofibers are characterized. Nanofluids are prepared by dispersing 0.5wt% of carbon nanofiber in the mixture of Sodium Dodecyl Sulfate (SDS) and deionized water to measure the thermal conductivity at varying temperature conditions. The results show that the thermal conductivity of nanofluid-based carbon nanofiber decreases with the increment in catalyst loading. The morphology examination indicates an increment in the diameter of carbon nanofiber during catalyst loading. Further surface area study for the nanofibers, based on nitrogen absorption analysis, confirms the possible mechanisms that scale down the thermal transport in nanofluid.