Under the guidance of bioassay, five alkaloids, one chromone and four steroids were isolated from the Phomopsis longicolla HL-2232, a fungus isolated from a mangrove Bruguiera sexangula var. Rhynchopetala. Their structures were identified as 6-aminopurine-9-carboxylic acid methyl ester (1), adenine riboside (2), uridine (3), N,N'-diphenyl urea (4), (2S,2'R,3R,4E,8E,3'E)-2-(2'-hydroxy-3'-octadecenoylamino)-9-methyl-4,8-octadecadiene-l,3-diol (5), 2-(2'S-hydroxypropyl)-5methyl-7-hydroxychromone (6), fortisterol (7), (22E)-5α,8α-epidioxyergosta-6,22-dien-3β-ol (8), cerevisterol (9) and β-sitosteryl linoleate (10). Among them, compound 1 was a new compound. Compound 5 was a new natural product, and its 13 C NMR spectroscopic data has not reported until now. Compounds 1~3 showed inhibitory activities against B16F10, A549, HL-60 and MCF-7. Compounds 1 and 3 exhibited the higher inhibitory activities against MCF-7 and A549 than positive control cisplatin with IC 50 values of 14.9 and 8.6 µmol•L-1 , respectively.