Based on C2R model in DEA,the continuous C2R model,which is employed to evaluate the relative efficiency among decision making units,is established in this paper when the inputs and outputs of decision making units are continuous functions that are defined at interval .At the same time,we give the definition of efficiency for decision making units,the definition of weak DEA efficiency,the definition of DEA efficiency,and we also propose a new method to study and solve the relative topics in economics and manegement.