abstract the volatile constituents of the fresh materials of hypericum cordatum were isolated by hydrodistillation and analyzed by gc and gc/ms. the leaves produced 0.04% of a yellowish essential oil and the flowers did not. the main components of the oil were myrcene (40.18%), -pinene (16.40%), and limonene (12%). the antibacterial activities of the oil against saccharomyces aureus and escherichia coli and the anti-fungal activities of the oil against the fungi cladosporium cladosporioides and c. sphaerospermum were evaluated. the oil showed an antibacterial activity against the bacteria s. aureus and anti-fungal activity against the two fungi.