Abstract: The feedback control of the control system of prices long-term volatility in efficient stock markets is discussed. The control  system model of prices long-term volatility in efficient stock markets is built. According  to the conditions of system complete accomplishability, both of the following issues are  discussed respectively: issue of taking stock market policies as single-control nput  collocating poles, and that of taking listed corporations policies as single-control  input collocating poles. According to the conditions of system incomplete accomplishability,  the equanimity problems are respectively discussed both when the stock markets don't develop  and when the stock market doesn't carry out macro-regulation. A dimension-minus state observer   is designed to estimate stocks' intrinsic value. By choosing the stocks' corresponding average    intrinsic value when the listed corporations are increasing in equilibrium as the target value,   we design linear multi-variables adjustor to make the closed-loop system become stable gradually   and the output of the system  track that target value. Through the feedback control we can improve  the interior structure and performance of the control system, and arrive at the purpose of regulating the stock markets.