This paper aims to study the probability distribution and the characteristics of the Shanghai Composite Index. We select 19901219—20160115 as sample time period, using amendatory BB turning point dividing method to get bull and the bear market. By extracting method of runlength sequences, we derive the probability distribution tables of each cycle up and down days for price observations’ sign and the statistical characteristics. Then, we give the comparative analysis and summarize the typical characteristics of the bull market and bear market. Finally, for a bull market period of 20140828—20150612, we select Industrial and Commercial Bank, Ping’an of China, China National Petroleum Corporation, SINOPEC and CITIC Securities to share the same calculation and analysis, we find that the trend of the five hot stocks in line with the market. Moreover, we can derive a conclusion that the method of run length sequence is simple and feasible when analyzing the characteristics of the stocks’ ups and downs by empirical analysis.