Abstract: This paper describes a new species, Stigeoclonium ovisporum Wei (Chaetophoraceae, Ulotrichales), from Yunnan and Sichuan provinces, China. In asexual reproduction of this alga, narrow oviod sporangia produce zoospores. The differentiation of vegetative cellsand reproductive ones is an advanced character in the genrus Stigeoclonium.

Key words: Stigeoclonium ovisporum, sporangia, hair