Abstract: This paper discussed the taxonomic problems of Trapa from Northeast China, such as the hierarchy of taxa. character judgement. basis for the determination of species and the phenomenon of Synonym. The Northeast of China is the mainly distribution centre of Trapa. The study on Trapa from this area can provided important evidences for the taxonomy of Trapa.

Key words: Trapa, Trapa mandshurica, Trapa potaninii, Trapa maximowiczii, Trapa litwinowii, Trapa bispinosa, Trapa pseudoincisa