Abstract: Through the decomposition of risk function, we first get an important indicator for the measure of nonlinearity of complex systems which has be traditionally neglected in the independently and identically distributed models or linear models. Then how to reduce risk is discussed. The we gradually introduce the departure degree, the disturbing degree and the information-decomposition ratio which constitute the five indicators together with the distortion degree and the risk function. Finally, we discuss how to control measure indicators of the stability center. It is also used to do a try for data analysis based on global thinking