摘要:We present the first faunistic report on the Laotian Cladocera from diverse habitats in Vientiane province, Central Laos.We counted a total of 70 species, belonging to 37 genera, which is realistically close to an estimated 77 species.The five most common species were Diaphanosoma excisum , Ephemeroporus cf.barroisi , Anthalona harti , Macrothrix spinosa and Chydorus cf.eurynotus .The fauna is typically Oriental/Southeast (SE) Asian, showing a strong similarity with neighbouring countries and especially Thailand.We discussed the current taxonomical status of the species and provided illustrations of the main taxa for future comparison.There are no surprising faunistic elements, except for a few new records for SE Asia ( Matralona freyi , Ilyocryptus thailandensis ).Our data is preliminary, as the fauna of Laos remains insufficiently studied.As for SE Asia as a whole, a significant number of taxa is in need of taxonomical revision.