Abstract: For the microseismic monitoring in a mining scale, the control of accuracy and stability of location is always a difficult problem. Based on the thorough analysis of the error of monitoring system caused by propagation velocity, coordinates of sensors and picking time, the term of integrity-error of location which can be taken as the fundamental principles to appraise studies on the monitoring engineering is proposed. Nonlinear analysis and transformation are conducted to realize the dimension reduction, the called plane-cutting location method is given and the basic nature of location is also clearly demonstrated. It is concluded that the integrity-error is the scale parameter and precondition in determining the location error. The accuracy and stability of location basically rely on the analytic geometry rather than numerical solution. The theoretical analyses and experiments both show that the plane-cutting location is a reasonable way of keeping the accuracy and stability of location in a acceptable level in a mining scale.