The bearing capacity of pre-bored grouted planted (PGP) pile under compression and tension is investigated based on a group of field compression and tension tests. The load-displacement curves of two test piles are compared and analyzed, and the effective stress method is adopted to estimate the shaft capacity of the test piles. The test results show that: the ultimate shaft resistance of PGP pile under tension is smaller than the ultimate shaft resistance of PGP pile under compression, due to the different stress conditions of the soil around the pile and the Poisson's ratio of pile shaft; the pile head displacement needed to fully mobilize the shaft resistance of test pile under tension is larger than the displacement needed to fully mobilize the shaft resistance of test pile under compression; a ultimate depth (or ultimate vertical effective stress) exists when the effective stress method is adopted to calculate the ultimate skin friction of the soil layers, and the value of the vertical effective stress corresponding to the ultimate depth should be adopted in the calculation of ultimate skin friction in effective stress method.