Abstract:  To design the geometric parameters of artificial pillar for deep mining，a new formula is developed to calculate the reasonable width of artificial pillar．Considering high-stress and large-disturbance in deep mining，the bearing mechanism of artificial pillar is clarified based on P’s theory．Through deduced formulas，mining span and mining depth are determined as the main factors affecting the reasonable width of artificial pillar，and the influence degrees of the factors are also calculated．The results indicate that the influence of mining span on the width of artificial pillar is greater than that of mining depth．The reasonable width of artificial pillar is calculated for deep mining in accordance with the engineering practice of one gold mine，and the rationality of formula and the influence degree of key factors are validated through field test．

Key words: artificial pillar, reasonable width, mining span, mining depth, influence degree