The specific inhibitors of cytoskeleton and histochemical stain were used to investigate formation of cell polarization during the early development of conchospores in Pyropia haitanensis.Polarized conchospores were observed twice:Anterior-posterior axis is formed in migrating conchospores.After migration,conchospores adhere to the substratum and then apical-basal axis is established.Meanwhile,composition of mucilage around conchospores was studied,and acidic polysaccharides and sulfated polysaccharides were found at the rear end in migrating conchospores and basal portion of up-righted conchospores.These results indicate that mucilage is involved in formation and maintenance of the cell polarization in conchospores.Inhibitors of cytoskeleton prevented the released conchospores from germinating through disturbing the anterior-posterior axis formed in migrating conchospores.It was found that they also affected the establishment of apical-basal axis for abnormal germinations in the inhibitors-treated migrated conchospores.These results indicate that cytoskeleton and mucilage are involved constantly in twice cell polarization formation of conchospores in P.haitanensis.