Abstract:Aggregation operators under the Pythagorean fuzzy environment and their applications to decision making are discussed.The Quasi-weighted geometric(QWG) operator and the Quasi-ordered weighted geometric(QOWG) operator are defined, and their natures are studied.Then, a class of aggregation operators called Pythagorean fuzzy aggregation operators are proposed, including the Pythagorean fuzzy order weighted average(PFOWA) operator, the generalized Pythagorean fuzzy order weighted average(GPFOWA) operator, the Pythagorean fuzzy order weighted geometric(PFOWG) operator, the generalized Pythagorean fuzzy order weighted geometric(GPFOWG) operator, the Quasi Pythagorean fuzzy order weighted average(QPFOWA) operator and the Quasi Pythagorean fuzzy order weighted geometric(QPFOWG) operator.A method based on generalized Pythagorena fuzzy aggregation operators for decision making is presented, and an example is given to illustrate the feasibility of the proposed method.