The volatility of the return of hedge funds,CRB index,S&P500 index and oil price exhibits abnormal situation both pre and ext financial crisis.The paper reveals that,in normal periods,all of the asset returns mentioned above possess stability features.S&P500 has Granger causality effect in advance and the size returns of hedge funds have stable explanatory power to the major assets in consideration.While during the crisis period,all returns of these assets become volatile heavily and the...