The paper shows the standard problems of risk measurement in the fields of finance.We give a general standard of risk measurement based on the characteristic and essential,axiom and theorem system of risk.Based on this standard,from variance,semi-variance,and β coefficient to VaR,such risk measurements were analyzed and developed,and some false ideas,methods were specified.Lastly,we present a risk measurement by combining the risk preference,contingent loss.We proved from the point of mathematics and analyzed from the point of econometrics that the measurement is a perfect and promising method.It has the important significance for risk management.