Naim Cagman - Department of Mathematics, Faculty of Arts and Sciences, Gazios- manpasa University, ۶۰۱۵۰ Tokat, Turkey
Serdar Enginoglu - Department of Mathematics, Faculty of Arts and Sciences, Gazios- manpasa University, ۶۰۱۵۰ Tokat, Turkey
Filiz Citak - Department of Mathematics, Faculty of Arts and Sciences, Gaziosman- pasa University, ۶۰۱۵۰ Tokat, Turkey

In this work, we define a fuzzy soft set theory and its related properties. We then define fuzzy soft aggregation operator that allows constructing more efficient decision making method. Finally, we give an example which shows that the method can be successfully applied to many problems that contain uncertainties.

Fuzzy sets, Soft sets, Fuzzy soft sets, Soft aggregation, Fuzzy soft aggregation, Aggregate fuzzy set