In order to know influence of inner moisture on thermal deformation of cement and emulsified asphalt mortar, change in length of specimens under different inner moisture conditions, namely vacuum dried, air dry and water saturated, was measured from -20 ℃ to 60 ℃. Results show that the inner moisture has a significant influence on thermal deformation of cement and emulsified asphalt mortar. The evaporation of inner moisture causes shrinkage notably as temperature rises. This shrinkage reduces its thermal expansion coefficient and can even lead to a negative thermal expansion around 20 ℃. In the case of water saturated condition, the transition of inner moisture from ice to liquid water between -5 and 5 ℃ results in another negative thermal expansion, too.