Abstract: On the basis of summarizing the definitions of initial pressure for subsidence of moist ground given by others, the paper gives a definition that the initial pressure for subsidence is a pressure to which the coefficient of subsidence controlled to be 0.015 corresponds after the loess was water-soaked. The pressure is a technical parameter of many performances for design of soil foundations, ground treatments, and elevations of subsidence of moist ground. The initial subsidence pressure has its regional variation regularity. From Qinghai in the west to Zhongzhou in the east, it appears to be higher at both ends and lower in the middle, and higher in the east and lower in the west in general. The initial subsidence pressure increases with depth in longitudinal direction in all loess areas. To understand and grasp these two regularities will help us to fully use loess foundations and choose the best technical option for their reform. Evaluation of the types pf soil foundation subsidence due to initial subsidence pressure can give the Highest, confidence meanwhile, the initial subsidence pressure is also a parameter for determining ground strength and forecasting soil deformation. The pressure value is used as a foundation bearing capacity in engineering at which the foundation can not produce subsidence deformation, which can not exceed the permissible deformation. Because the initial subsidence pressure is a load at elastic deformation stage after loess soakage. The load-relevant deformation is almost at 0.8 cm. To test the initital subsidence pressure, the single-and couple-line methods can be used in laboratory. But the couple-line method is usually adopted in production. To test the pressure in the field, a water saturation method is used, and pressure plate area of 2500 cm2 is adopted.