Aquatic Oligochaeta is a notable animal group in freshwater environment such as streams, rivers and lakes in view of its biomass and species richness. Taxonomic studies of this group, however, have hardly been performed in Korea. Here five naidid oligochaete species are reported - Slavina appendiculata, Pristina longiseta, Pristina biserrata, Chaetogaster diaphanus and Nais variabilis - from the Seokhyeoncheon Stream in Yangju and from the Changreungcheon Stream in Goyang, Gyeonggi-do. Aquatic oligochaetes attaching on aquatic vegetations were collected with a plankton hand net. An image and description on Nais variabilis new to Korea are provided.