Abstract: The dip angle of Liujia mining orebody of Shangdong province Xintal gold mining is 0°～22° and the average thickness is 4.17 meters.The liujia mining orebody is belongs to the Monzonitic granite type deposits, so, the room and pillar open stope filling later method is adopted by using the scraper. The stope area is 400 square meters an has 14 pillars. Due to number of the pillar is too much, so it makes the mine production more difficult. Through numerical simulation optimization, the number of pillar reduce to 4, the diameter of pillar increased to 5 meters. The research results indicated that, reducing the number of pillar is good for increasing the stope operation area,and good to the ore transportation in the stope.In addition, according to the experimental results, the round supporting mechanics is better than the square one, witch provide convenient conditions for forming the arch stope roof.

Key words: Room and pillar mining, Number of pillars, Numerical simulation, Optimization research