Researches on gypsum's TCM curative effect and mechanism from the perspective of its geological formation are seldom seen in domestic and overseas papers. Based on the new analyzing method of combining geology and TCM theories, this paper gets some results and conclusion on gypsum as follows: 1) the gypsum is formed through intense evaporation, therefore it has the characteristic of pungent and cold, and it can resolve flesh and clear heat; 2) there is high Mg/Ca in the aqueous solution that forms gypsum, so it can urge the calcium to be absorbed inside animal bodies; 3) gypsum consists of saline minerals of calcium, so the abundant supply of calcium can promote the knitting of bones.