In the study, a three-parameter model was presented to calculate the thermal conductivity at full range of degree of saturation (S) for fine-grained soils based on the Fredlund and Xing model and the normalized thermal conductivity method. Three parameters (a, b, c) of the new model are determined by two equations and a measured point at a certain S. Two equations were obtained by the correlations between the parameters a, b, c and the basic properties of 30 Canadian soils by regression analysis. Moreover, the relationship between the thermal conductivity and S at full range of S was defined as the thermal conductivity curve (TCC) and was divided into 3 regions for the improvement of the calculation result. According to the sensitivity analysis, it is found that the calculated TCC is the most reliable when a point is measured in the Region 2. In addition, the new calculation model was also verified by 6 Chinese soils, suggesting the new model could present a good calculation result (R-2 = 0.97) for the TCC. (C) 2018 Elsevier Ltd. All rights reserved.