Two new bromotyrosine alkaloids, ma'edamines E (1) and F (2), were isolated from an Okinawan marine sponge Suberea sp., and their structures were elucidated by the analyses of spectroscopic (UV, IR, and NMR) and spectrometric (MS) data. Ma'edamines E (1) and F (2) are the second and third examples of natural products possessing an N-alkyl-3,5-diethyl-2-propylpyridinium moiety. Ma'edamine F (2) is the first bromotyrosine alkaloid having both pyridinium and quaternary ammonium moieties. Ma'edamines E (1) and F (2) showed moderate cytotoxicity against L1210 murine leukemia cells in vitro.