The structural analogues of cumambrin B(1, 2, 3, 4) were isolated from the flower of Chrysnathemum boreale Makino. The structures of compounds were determined by two-dimensional $^{1}H-^{1}H$ COSY and $^{13}C-^{1}H$ COSY spectra with the aid of homonuclear and heteronuclear double resonance experiment. The stereochemistry of compounds has been verified from single crystal X-ray diffraction of cumambrin A(2). the antimicrobial activities of these guaianolides have been studied.