Two new bromoindole alkaloids have been isolated from the ethanolic extract of the red alga Laurencia similis. On the basis of chemical and spectroscopic methods (including 1D and 2D NMR technique), their structures have been elucidated as 2,2′,5,5′,6,6′-sixibromo-3, 3′-bi-1H-indole and 3, 5-dibromo-1-methylindole, respectively. © 2008 Xiao Bin Zhu.