Abstract: The construction process of post-grouting on the tip and side for ultimate bearing capacity improvement is presented.10 piles with post-grouting on tip and side and 2 unpost-grouting piles are tested and analyzed.The results indicated that the length and integrity of piles are satisfactory.The untimate bearing capacity of post-grouting piles are 70% improved at least than that of unpost-grouting piles,making maximum vertical static loading of this time testing piles as ultimate bearing capacity is safer and designing single pile ultimate bearing capacity as 8 800 kN is secure.Post-grouting on the tip and side for ultimate bearing capacity improvement of the foundation pile is feasible but the proper grouting stata choosing.The accurate grounting volume and pressure controlling in the constrution of piles are needed