This chapter introduces taxonomic information about soil nematodes present in the grassland transect. It starts by presenting general information about morphological terminology and the structure of nematodes that are taxonomically important. It then reports on the background of nematode life strategies and their potential roles in ecosystems. At the end of the chapter, the general characteristics of 32 nematode families are explained and drawings and pictures of 66 nematode genera are given along with their key characteristics for the identification of nematodes in the grasslands of northern China.
