This paper studies the relationship between the degree of compactness of the pile structure foundation and how it will tilt under different wave condition. In the lab experiment setup, we use a periodic force generated by a magnetic coil to simulate the wave force impending on a scaled down model pile. With this setup, forces with different periods and magnitudes are used to find out the critical wave condition under which the pile will tilt, and it relationship with the results, engineering aspect of setting up a pile structure in the sea will have a better reference in the design stage.