It has been discussed for many years in China whether the young buds of Porphyra haitanensis can release monospores. The problem was studied in many aspects, especially for the condition of cells releasing, for the tendency of cells development and differentiation, and for the ultrastructure.After a comparison between P. haitanensis and P. yezoensis, the young buds of P. haitanensis were found releasing some cells under special culture conditions,which had been regarded as monospores. However, they are the same as vegetative cells of P. haitanensis and different from the monospores of P.yezoensis in the microstructure, ultrastructure, releasing rules and the developmental results of cells. The above results of experiments indicate that the buds of P. haitanensis can not release the real monospores.