Abstract：Based on the test results of pressed piles by static load test and high strain dynamic test in an engineering test，as well as the analysis of mechanical behaviors of pile shaft material and developing behaviors of soil resistance and the load transfer behavior，an analysis of errors of Q-s curve simulated by high strain dynamic testing method is made. The settlement of pile calculated by high strain dynamic testing method is higher than that of pile tested by load test when load is smaller；and it is bigger than the result of load test when load is higher. These errors are relative with the mathematical model about pile shaft concrete and soil resistance in high strain testing. Concrete is thought as elastic body in high strain testing，but actually it is nonlinear，this brings about some errors in Q-s curve of pile simulated by high strain dynamic testing method. The model of static soil resistance in high strain testing，which is thought as elasto plastic model，is not the same as the actual developing behaviors of soil resistance；and the settlement of pile in high strain testing is smaller than that in static loading test；these are major factors which bring about errors in Q-s curve of pile simulated by high strain dynamic testing method. These factors should be considered when the Q-s curve is simulated by high strain dynamic testing method.
