The gravity inclination method, which has been utilized for measuring the heat transport capability of a heat pipe, is applied to estimate the reflux force of the Marangoni effect caused by concentration difference in a two-component heat pipe in a gravitational field. It is shown that the Marangoni force become larger for heat pipes containing water-ethanol or water-acetone solution of relatively dilute concentration, as expected by previous microgravity experiments. Experimental results of heat pipes containing water-acetone mixture, which were different from those of water-ethanol mixture, do not agree well with the results predicted by the method as designated in the previous paper. However, these are explained by considering the difference of NTU (number of transfer unit) of each two-component mixture.