Abstract: Pile tip grouting has been widely adopted in engineering in recent years. However, the improvement effect on piles with different lengths is rarely studied. Based on the parameters verified by finite element of a project in Tianjin and considering the enhancement of grouting, the bearing capacity of piles with different lengths is analyzed. The finite element analysis shows that the ultimate load raises 25% ～ 71% for single piles with length of 20 ～ 100 m after grouting. The improvement effect of grouting is very significant for short piles, while that for super-long piles is not the same as that for short piles especially on tip resistance. Tip grouting is propitious to the load transformation to the lower part of the pile, and it is also helpful for the exerting of the tip resistance and the shaft resistance of the lower part of the pile.