The invention discloses a method for conserving the Yangxicai juvenile sporophyte sprout, with the following characteristics: culturing it in the sea tangle nursery pool with height of 30-50 cm or in the prawn nursery pool with height of 80-100 cm, the culture temperature range is 5-20 deg, the culture salinity range is 20-35%, the culture irradiation magnitude is 5-50 ª–EM-2S-1, stimulating the recycle water and changing water timely. The advantage of the invention is that the juvenile sporophyte sprout can be maintained for over three months, the sprout forming rate can amounts to 76%, and the sprout can satisfy the productive norms and meet the breeding need. The invention can conserve the Yangxicai juvenile sporophyte sprout for experimental material at any time, the individual size is approximate with each other and can be used for the research of algae morphological change, bio-ecology and toxicology, and the stimulation by the running water is facilitating for normal growth of the Yangxicai juvenile sporophyte sprout with a certain density.