We say that a paratopological group G is pseudobounded (?-pseudobounded), if
for every neighborhood V of the identity element e of G, there exists a
natural number n such that G=Vn (G = U?n=1 Vn). In this paper, we mainly
discuss the pseudobounded and ?-pseudobounded paratopological groups. First,
we give an example to show that a theorem in [4] is not true. And then, we
define the concept of premeager, and discuss when a pseudobounded
paratopological group is a topological group. Moreover, we also discuss some
properties of ?-pseudobounded topological groups, and show that the class of
connected topological groups is contained in the class of ?-pseudobounded
topological groups. Finally, some open problems concerning the
paratopological groups are posed.