Abstract: The liquid phase,a very active part in the soil body,can change the connections among particles through the isolation of solution ingredient in the pore and the dissolving of granular mineral,then influence the structural intensity of the soil body.Based on the laboratory test that changes the kind and content of the solution in the clay structural pore,the mechanical behavior under thermal effect of different soluble salt ingredients in the soil structural pore is discussed.The influence of ingredients and content of pore solution on structural and mechanical behavior of viscous soil under thermal effect is studied.The test results show that when the temperature increases from 40℃ to 6 0℃,the time of thermal effect is 16 8 h,the cohesion of the clay added MgCl2 ingredients has the greatest increasing range,followed by that of the clay added Fe and MnSO4 ingredients,and that of the clay added FeCl3 ingredients has a little increasing range.On the contrary,the cohesion becomes smaller after adding Ca(OH)2.Under the same condition,the internal friction angle of the clay added FeCl3 and Na2S2O4 ingredients is reduced,the group added Fe and AlCl3 has a little change,and the increasing range of clay added MgCl2 is similar to that added Ca(OH)2,second only to the clay soaked with deionized water.