A strain of Takayama pulchellum was isolated during a bloom in Xiamen Harbor in 2003. Morphology was observed under LM and SEM. The vegetative cells are relatively small in size, ranging from 20～23μm long and 14～20μm wide. Cells are broadly oval with a conspicuous and well-defined sigmoid apical groove present on the epitheca. The apical groove is a characteristic reversed S-shape. The nucleus is located in the top part of the cell and most cells’ cingulum do not displace, which are different from the type species. The growth rate reached the highest value, about 0.43, at salinity of 28 and dropped when salinity decreased. The cells ceased growing when salinity went down to 16, however, more than 80% of the cells could survive for 48h when salinity ranged from 8 to 16. Survival was not observed at salinity lower than 4. Best growth rate of Takayama pulchellum occurred at temperature of 24 and 27℃, which was above 0.50. Growth rate dropped sharply to about 0.35 when temperature increased to 30℃. PSP (paralytic shellfish poisoning) and NSP (neurotoxic shellfish poisoning) analysis did not reveal any toxin in this strain. The D1-D2 region of LSU (large subunit) rDNA and total ITS1-5.8S-ITS2 were amplified, cloned and sequenced. The partial LSU has 721bp and shares more than 99% similarity to the same species whose data was deposited in the Genbank. A phylogenetic tree was constructed using ITS sequence of 18 species, showing that Takayama pulchellum is closely related to Karlodinium micrum. The genus of Akashiwo, Karenia, Karlodinium and Takayama could be separated from Gymnodinium genus approximately using ITS sequence.