<正> An account of the all-artificial spore-collecting cultivation of Tiaoban-zicai （Porphyra yezoensis Ueda） in North China, carried out mainly after the Great Proletarian Cultural Revolution, is presented here. Scientific and technical workers integrating themselves with porphyra-cultivating peasants and learning the experiences of the masses, have eonducted investigations and thereby improved the cultivation techniques principally along three directions: （1） By employing comprehensive techniques in the culture of the conchocelis stage of tile porphyra, we have made at appropriate time the conchocelis discharge large numbers of conchospores, each shell （30—40 cm2 in area） from 5 millions or more spores to as many as 80 millions in best cases. （2） Taking the discharge of large numbers of conchospores as the basis, and sufficient light intensity and vigorous agitation of the cultures as the conditions for materializing all-artifical spore-collectlng, we have developed a simple but efficient technique by em
