In this paper, a more efficient preparation method for Co catalyst supported on carbon nanotubes (Co/CNTs) was investigated by introducing plasma technique for precursor decomposition. The microstructure and the Fischer-Tropsch (FT) performance of the Co catalysts prepared by different preparation methods were also compared. It was found that Co/CNTs catalyst can be prepared by calcination at 200 degrees C in either Ar or air atmosphere but can not be obtained at high temperature in air atmosphere. High calcination temperature in Ar atmosphere caused the aggregation and reduction of the cobalt species, which are not good for improving the FT performance. However, dielectric-barrier discharge (DBD) plasma treatment can replace the traditional calcination method to prepare Co/CNTs catalyst with uniformly dispersed Co particles. The cobalt catalysts prepared by DBD plasma can achieve similar FT performance with the Co catalysts calcined at 200 degrees C. A big advantage of plasma treatment is to make the precursor decomposed at lower temperature with less energy input in a short period of time. So plasma is proved to be an efficient alternative approach for Co-based catalyst preparation for FT synthesis. (C) 2014 Elsevier Ltd. All rights reserved.