This paper aims to study if there is price clustering in stock markets of China Mainland.The study indicates that there is price clustering in stock markets of China Mainland,with 0,5and 8 are the most frequent,4 is the least frequent.In addition,bull or bear market,high-price or low-price stocks,the marked difference of price clustering is that quote focus to 0,avoids 4.Rationality vs.Superstition theory which were proposed by this paper can effectively explain these phenomena.