The red clay in Kunming New Airport had negative effect, such as more settlement, the differential settlement, the poor property of compactness and water content too difficult to control during construction. Therefore, there were a serial in situ tests for the red clay foundation: (1) the red clay foundation was treated by the dynamic consolidation method(DCM) with cushion and the gravel pile method, then the embankment of red clay, (2)the natural foundation of red clay was filled directly by red clay and Douposi highly weathered material as the embankment material. Their deformation and pore water pressure rules of natural red clay foundation, foundations treated by DCM and gravel pile were obtained on the condition of high embankment by monitoring of settlement, horizontal displacement and pore water pressure. Test results showed that (1)during the embankment construction period, the settlement of DCM test region was maximum, the gravel pile test region second, the natural foundation of red clay was minimum.(2) the low velocity of layered horizontal displacement indicated that the slope was stable. (3) the increasing and dissipation of pore water pressure was accordance with the embankment history. (4) because it was on the embankment construction period, the monitoring data just reflected the deformation rule in the initial stage of loading.