Seaweeds are multicellular marine benthic algae including green, brown and red algae. They consist of about 8,000 species and play an important role as a primary producer in rocky coastal ecosystems. My research interests include the diversity of seaweeds, especially their phylogeny, evolution and speciation. I study on the diversity of seaweeds by morphological observation, molecular technique and crossing experimant and revise the classification system or describe a new species.