Cobalt-nitrogen-doped mesoporous carbon (Co-N-C) is synthesized as a host for lithium-sulfur batteries. With the Co-N-C composite as a sulfur host, the initial capacity of lithium-sulfur batteries is as high as 1290.8 mA h g(-1) at 0.2 C, and Li-S batteries still exhibit good cycling stability and high capacity with a retained capacity of 795.7 mA h g(-1) and a nearly 100% coulombic efficiency after 300 cycles. The good performance of Li-S batteries can be attributed to a higher specific surface area and pore volume of the carbon matrix and good chemical affinity of Co and N elements toward polysulfides. It is found that Co-N-C composite can effectively adsorb lithium polysulfide by physical, chemical adsorption and well inhibit the shuttle effect. In addition, Co-N-C composite which act as a catalyst can also significantly promote the conversion of polysulfide, accelerate the kinetics, thereby improving the performance of Li-S batteries.