To provide a method for accurately measuring static earth pressure and active earth pressure in an original position ground used in design of an underground building frame external wall of a newly constructed structure or an earth retaining wall or the like by using an existing underground building frame outer wall when a structure is newly constructed by dismantling the existing structure having an underground building frame.

In the method for measuring the static earth pressure in the original position ground acting on the existing structure having the underground building frame, a hydraulic jack 5a is installed on a slab 2 of the underground building frame 1, and the load of the hydraulic jack 5a is increased to bear axial force acting on the slab by the earth pressure on the hydraulic jack 5a. The slab 3a of a part of an interval installing hydraulic jack frames 6a, 6a in a state where horizontal deformation is not generated in the underground building frame external wall is dismantled, and the static earth pressure is obtained by measuring load acting on the hydraulic jack 5a.