In orther to isolate antibacterial substances from the flower of Chrysanthemum zawadskii Herbich var. latilobum Kitam., the chloroform fraction was fractionated according to the activity against B. subtilis, S. aureus and V. parahaemolyticus. Two antibacterial substances were isolated and purified by preparative TLC and recrystallization. Compound Ⅰ showed activity against all the tested bacteria and compound Ⅱ exhibited the activity against B. subtilis and V. parahaemolyticus except S. aureus. Compared to benzoic acid and sorbic acid which are being used as food preservatives, compounds Ⅰ and Ⅱ showed about five-fold stronger antibacterial activity against B. subtilis and V, parahaemolyticus. On the basis of spectrometric studies including ¹H-NMR, ^(13)C-NMR, DEPT, ¹H-¹H COSY, ^(13)C-¹H COSY and Mass, compounds Ⅰ and Ⅱ were identified as angeloylcumambrin B and cumambrin A, respectively. This is the first report of the isolation of angeloylcumambrin B and cumambrin A from this plant.