PROBLEM TO BE SOLVED: To provide growth methods of brown algae that can efficiently grow brown algae while inhibiting microalgae and the like from growth and proliferation.SOLUTION: The present invention provides a growth method of brown algae, characterized by growing brown algae by putting either one or more of spores, immatures, and adults of brown algae into an adjusted sea water which is adjusted so that an iron concentration becomes 5 μg/L or more, and irradiating with light having a wavelength of 400-500 nm and a light intensity of 10 μmol/m/s or more to less than 40 μmol/m/s.SELECTED DRAWING: Figure 4【課題】微細藻類などの生育や繁殖を抑えながら、効率的に褐藻類の生育を行なうことができる褐藻類の生育方法を提供する。【解決手段】鉄濃度が５μｇ／Ｌ以上に調整された調整海水中に褐藻類の胞子、幼体又は成体のいずれか１種以上を入れ、波長が４００～５００ｎｍであって光強度が１０μｍｏｌ／ｍ２／ｓ以上４０μｍｏｌ／ｍ２／ｓ未満の光を照射して、褐藻類の生育を行なうことを特徴とする褐藻類の生育方法である。【選択図】図４
