Abstract: Mixed fermentation technique was applied to culture two marine-derived mangrove endophytic fungi (strains Nos. 1924# and 3893#) from the South China Sea in this paper. The crude extracts from the fermentation liquids extracted by ethyl acetate showed significant bioactivities of killing pests Heliothis armigera Hühner and Sinergasilus spp. in the primary bioassay. Two secondary metabolites A and B were isolated from this crude extracts, and elucidated by spectral methods as 6-methylsali-cylic acid(A) and cyclo(phe-phe)dipeptide(B) respectively. Compounds A and B were not obtained from these two strains by pure fermentation. Compound A was responsible for the significant biocide activities of the crude extracts.