Abstract: This paper, with the case study of all the A-Stock on-market companies in Shanghai, discusses the following two major information Revelation of the on-market Companies: one is that in 2001 and 2002 annual reports the benefits of the companies reached the growth beyond 100% or 30% than the same period of last year; the other is that in the first half of 2002 the stock-control rights were transformed among the companies. The findings of the analysis is that there is an obvious relativity of the major information revelation of the on-market companies and the unusual stock fluctuation, from which the serious low-down trade on Chinese stock market has been exposed. This paper aims to present some suggestions and countermeasures for the improvement of the corresponding monitoring and management