This book consists of three major parts viz., study of the topological notions of fuzzy sets, rough sets and soft sets. The first part consists of the work on fuzzy topological space, where two different types of generalized notions of fuzzy closed sets, namely, fuzzy g*s-closed sets and fuzzy weakly-closed sets are introduced and studied. In the second part, works on topological structures of rough sets are presented. It deals with different approaches in studying topological notions of rough sets. The third part contains of topological structures of soft sets. Also, topological notions are examined on a hybridization of soft sets and fuzzy sets.