Collapsibility is one of the important properties of loess. When collapses of loess occurred, soil pressure and water content changed correspondingly in sequences. In this study, water immersion tests were conducted with the collapsible loess in a field trial pit. With deployment of the sensors and tension meters in and around the experimental site, a large amount of data was collected regarding the changing patterns and rules of soil pressure and water content. The results show that the soil pressure and matric suction in the lo-ess layers decreased during the experiment. During the deformation, abrupt subsidence of loess often oc-curred when the soil pressure was reaching its minimum and the water content was close to saturation.