The pollen grains of three families, i. e., the Chloranthaceae, Piperaceae, and Saururaceae incIuding six genera and eleven species have been studied. Pollen morphology among species of the same genus is frequently similar, but pollen grains of these different genera are sufficiently different so that they usually can be distinguished readily, excepting members of Houttuynia, Saururus, and Piper. On the basis of pollen morphology, plants of Piperaceae are closely related to those of Saururaceae.