动、静态投资回收期及财务净现值（ＦＮＰＶ）和经济净现值（ＥＮＰＶ）是确定工程项目是否能接受的重要参数，而基准折现率和社会折现率又是项目价值判断的标准。着重分析了投资回收期与折现率之间的关系和意义，并研究了项目进行经济评价时，投资回收期和折现率的确定方法和作用。 The dynamic and static payback periods and the financial net present value (FNPV) and economic net present value (ENPV) are important parameters to determine whether the project can be accepted. The benchmark discount rate and the social discount rate are also the criteria for project value judgment . Emphatically analyzed the relationship between investment payback period and discount rate and its significance, and studied the method and effect of investment payback period and discount rate in project economic evaluation.