Recently, information and communications technologies (ICT)have been widely used in the air-conditioning field, and high-performance and density ICT facilities have been rapidly growing. At the same time, the heat generated per unit area of a normal data center, where the servers and routers are concentrated, in an ICT facility is an ICT facility is an extremely serious problem・ Therefore, this study aims to investigate the performance and characteristics of the server spot cooling heat transportation system adopting CO_2 as the working fluid to prevent the occurrence of hot spots and decrease the power consumed by a conventional overall air conditioning system installed at a data center with experiments and simulations. In the result, heat transfer flow rate of this system was higher in forced cycle than in natural cycle, but heat transportation performance factor was lower in forced cycle than in natural cycle.