This paper discusses the relative efficiency analysis of the dea model with uncontrollable inputs and undesirable outputs under circumstance restriction and proposes the definitions and theorems about the relative efficiency of decision making units ( dmus ) 摘要对环境约束下包含不可控输入、非期望输出的dea综合模型的相对有效性进行研究,给出决策单元有效的定义及定理。