Abstract: The paper firstly points out the causes and the characters of the negative friction of pile foundation, and also introduces its unfavorable effects on pile foundation. According to some correlated standards and regulations, then it gives some calculation methods of negative friction of pile foundation, including: the location of the neutral-point, the determination of the negative friction and the bearing-capacity check of the pile founding. Lastly, it introduces some methods to reducing the effect of the negative friction of pile foundation.