Pile sinking during pile driving is common.A sudden drop of a pile after a strike from the hammer may cause a serious accident，such as the pile falling out of the drive cap or damage to the pile from high tension stress.Pile sinking also often causes a large deviation between the drivability prediction and the measured blow count.Therefore, an accurate assessment of pile capacity after pile sinking becomes an important problem to address in practice.In this paper，two projects in the East China Sea are chosen to analyze.Based on the results of dynamic load tests in the field and pile driving records，the influence of pile sinking on pile capacity at the end of driving （EOD）is studied.The analysis results show that pile sinking will lead to a significant decrease in the total energy used in pile driving.The results from CAPWAP show that the unit friction of a soil layer where piles run off is close to zero，while the pile end resistance shows no obvious abnormalities.This indicates that the decrease in pile capacity caused by pile sinking is mainly from friction reduction.In this instance，the pile capacity reduction resulting from pile sinking can reach a maximum of 17% of the designed value.