Abstract: This paper reported and described a new species of genus Selenochloris(Volvocales)——S.jaoii H.J.Hu et Y.X.Wei sp.nov.,according to late Prof.C.C.Jao’s manuscript note and figures.Cells compressed,in broad side-view oval-shaped,posterior end with two lobes,rounded,papilla absent;in la-(teral) view oval-shaped,posterior rounded;2 flagellates,anterior,terminal,1.5 times as long as the cell;Chloroplast cup-shaped,pyrenoid absent,with one large nuclear;cells 10.5-12 μm long,8.75 μm broad,(6 μm) thick.This algae comes near S.reinformis(Playfair) Ettl,but differs from the later in broad side view,the cells kidney-shaped.