Abstract: The optimal mining depth of gently inclined ore deposit along the inclination not only determines the width of ore block, but also decides the stage height of the development of ore deposit when the mine field spreads along the trend of the ore deposit. According to the characteristics of the stage height optimization of gently inclined and thin ore deposit, this paper separately established the functional relationship between the cost of basic construction, the transportation cost of the ore, the ventilation cost, the drainage cost and the stage height by using the linear regression and limited with compared method for the research object of mine in western Hubei. It is achieved that the relationship between the stage height and the unit cost of the ore is the quadratic function. The research result shows that 23.625 meters of the stage height is optimal height in mining with lowest costs per unit ore when the length of the Minefield is 1000meters and the thickness of the ore is 3.7meters and the dip angle is 8°.

Key words: Iron mine, Gently inclined and thin ore deposit, Stage height, Linear regression