The DNAs were extracted and purified from several cryptogams such as Bryophyta(moss), fern(Pteridaceae, Botrichioceae), Salvinaceae, and Equisetaceae. Major bases of DNA were analyzed, and following results were obtained. 1) Five species of the mosses examined all have G-C type of DNA (53-58%), as that of algae. 2) Pteridaceae, Botrichioaceae and Salivanaceae have similar DNA base compositions (44-45 % G + C), while Equisetaceae has the DNA of 38 % G + C. 3) In gymnosperms, the DNAs of pollens of ginkgo and cycad are of high A-T type (32-33 % G + C), and have similar base composition. G + C content of the DNA of pollens of Podocarpus is 30 %. 4) The DNAs of pollens of Pinus (5 spieces.) and Abietaceae (2 spieces.) are also of high A-T type, possessing 33-34 % and 37-38 % of G + C content respectively, thus, the DNA base composition of pollens of several gymnosperms is similar in a group under the same classification, Thus, the DNA base compositions of pollens are supposed to be of some divergence, and correlate well with other taxonomic criteria.