Four compounds containning nitrogen have been isolated from the sponge Phacellia fusca Schmidt, collected from the Xisha Islands in the South China Sea. The structures of these compounds were characterized by ~1H NMR, ~(13)CNMR, HMQC, HMBC, ~1H-~1HCOSY, FABMS and EIMS as N, JV'-bis[2-ethoxyl-l(Z)-vinyl] urea (1), 2-bromoaldisin (2), aldisin (3) and dibromophakellin (4). Among them, compound 1 is a new urea, containing a symmetrical partial structure, named as phacelliaurea A. Compound 4 is a known guam'dine alkaloid, first isolated from the sponge Phacellia fusca Schmidt, and the data and assignments of its ~(13)C NMR was first reported.

Key words: marine sponge, ALKALOID, 1HNMR, C13NMR, UREA