In this paper, we introduce a method for measuring thermal conductivity of paper by a hot disk system. Hot disk system has been used to measure the thermal conductivity of various materials. To our knowledge, thermal conductivity has not been emphasized in paper industries. However, in modern digital printing technology, the heat transfer is very important. This motivates us to investigate the thermal conductivity of paper coating. We have studied the effects of coating thickness, paper base weight and coating method on thermal conductivity. The thermal conductivity is further correlated with other physical properties of paper. Our investigation demonstrates that both the thermal conductivity and porosity will respond to the change of coating weight, basis weight and coating methods. Therefore, the thermal conductivity measurement should be a useful tool to provide guidance for coating material selections. It also should have application for coating formulation development in order to achieve an optimum substrate characteristic for laser printing.