Abstract:So far, more than 100 species of genus Anabaena have been recorded in the world, and about 50 taxa were described in China. During our recent field investigations for water-bloom forming cyanobacteria in China, several filamentous cyanobacterial species were examined in the samples. In this study, we demonstrated that two Anabaena species as Anabaena viguieri Denis et Frémy 1923 and Anabaena smithii (Komárek) Watanabe 1992, had never been reported in China, and they are newly described and discussed in the present study.