A group of experiments were performed to determine the effect of the plant of a seismometer on the motion imparted to it by the ground. It was found experimentally that a seismometer and the ground form a resonant system. The characteristics of this system depend on the type and condition of the ground surface, the method of planting the seismometer and the seismometer weight and base area. Methods were devised for obtaining a satisfactory seismometer plant in areas where ordinary surface plants introduce distortion into seismic records. The mathematical expression of Seismometer Response and Ground Admittance in terms of experimentally measurable quantities is given in the appendix.