Abstract: This research project was a field observation study and we examined the ethnobotany, phenology and antibacterial effects of two species of H. perforatum and H. androsaemum. The investigation of phenology showed these plants initiate vegetative stage at the early April to June, with wide dispersal and density in humid temperate to dry-cool climate in heavy texture soil and non saline in 10-2400 m from sea level. The ethanolic extracts of flowering aerial parts of either species exhibited a good antibacterial activity against Staphylococcus aureus and Entrococcus faecalis, with the diameters of growth inhibition zone in the rang 25, 26 mm in H. perforatum and 16, 20 mm in H. androsaemum, respectively. Weak antibacterial effects were seen in the infusion and aqueous extracts. Present data show that Gram-negative bacteria are resistant toward all of different extracts. We conclude that the extract of Hypericum species should be used when the etiological agent of infection is a Gram-positive bacteria.