A Study of Some Aspects of Topologized Groups A topological group is a mathematical object along with algebraic and topological structures. In this thesis our motivation is to study topological properties in the presence ofalgebraic structure particularly when the mappings are not continuous. It is a common question in topological algebra that how the relationship between topological properties depends upon the underlying algebraic structure. It is noticed that weaker the restriction in between algebraic structure and topology are, the larger is the class we obtain. Since we have weakened the condition of continuity and replaced it with the weaker form that is semi continuity and irresolute mapping and resultantly obtained s-(S-, Irresolute, Irr-) paratopologized or topologized groups. The purpose of this thesis is to give a mostly self contained study of s-(S-, Irresolute, Irr-) paratopologized or topologized groups. It is shown that every irresolute paratopological group is Irr-paratopological group as well as s-topological group. Every paratopological groups is s-paratopological group as well as S-paratopological group, and every Irr- paratopological group is S-paratopological group. Counter examples are given to show that such paratopological groups are generalized forms of the corresponding topologized groups. We have also defined and studied quasiboundedness of irresolute paratopological groups and s-paratopological groups. New notions- quasi bounded and - quasi bounded homomorphisms are introduced and discussed. In Chapter number six, we have defined semi-quotient mappings which are stronger than semi continuous mappings. Various interesting and important results on semi-quotients of paratopologized groups are proved. We have also studied semi connectedness for topologized groups.