As Franco-Belgian Dexia bank going bankrupt in the European debt crisis in October 2010, systemic risk went into the public field of vision once again.Commercial bank's systemic risk possesses the characteristics of complexity, uncertainty and negative externality.The β coefficient of Chinese commercial banks was measured by using the Sharp market model in order to observe changing trends of Chinese commercial bank's systemic risk since the European debt crisis, especially at the beginning stage of European banks coming to crisis.Some corresponding suggestions were presented.