In order to solve the problems concerning the design of large diameter steel pipe piles of open end for the wharf foundation, comprehensive tests on the piles were carried out, along with detailed survey of the ground conditions. The test piles are two large diameter piles (φ1117.6mm) and one small diameter pile (φ600m
m), which are instrumented with strain gauges. Important conclusions from the tests are as follows: 1)Smith's method provides good estimation for dynamic behavior of pile driving. 2)The calculated bearing capacity according to the dynamic formulae are 40-90% larger than the measured results. 3)Although skin friction and point bearing can be evaluated by the method generally used for design in Japan, the large diamter piles of open end have loose internal plug and have small point bearing capacity. 4)Contribution of rubble mound to lateral resistance of a pile is small; 1-3 were obtained from the back-analysis for the N-value of the rubble mound.