摘要:The , a new appearing financial risk-manage tool, have been applied widely. Many financial setups have accustomed to measure the risk of a portfolio with the . So it is very necessary to discuss the portfolio choice problem under the constraint. In this paper, by setting and solving the portfolio choice model under the constraint, we illustrate that the use of the constraint reduces the array of choice to a more manageable range. The probability of target , therefore, can be thought of as a risk tolerance assessment tool (when coupled with another measure of risk).