UDP-glucose/galactose-4-epimerase (UGE) catalyzes the interconversion of UDP-glucose and UDP-galactose. Oryza sativa contains four UGEs. Expression of OsUGE3 was higher than other OsUGEs in all tissues except the stem. OsUGE1 expression was enhanced after drought, salt or UV-irradiation stress. Four rice UGEs (OsUGE1-4) were cloned by polymerase chain reaction and sequenced. OsUGE1-4 were expressed in Escherichia coli with glutathione S-transferase fusion protein and purified. All four OsUGEs could covert UDP-glucose into UDP-galactose better than vice versa. Kinetic parameters of OsUGEs showed that OsUGE1 was most efficient. These OsUGEs could be used for biosynthesis of various UDP-sugars, which serve as a cosubstrates of UDP-dependent glycosyltransferase modification reactions of antibiotics or flavonoids.