Beacuse of actual mining situation in two huai coal mine with representative sections coal mine are collected,concludeod,trsted and lresearched,this paper expounds meaning,kind,action,restricting connections,factors of influence,counting method and defining prinple with waterproof pillar,compressing height to reasonable size scope with waterproof pillar is a main way.

Base on the existing problems of coal and rock pillar height in No 1 Level of the mine, the paper analyzed the previous data and disadvantages of the pillars and provided the factors effected to the coal and rock pillars with the geological background and characteristics.