Total phenol contents of leaves of garden orache (A.hortensis L.) growing in greenhouse and field conditions changed between 130.14 mgGAE/100g and 281.11 mgGAE/100g to371.94 mgGAE/100g and 477.50 mgGAE/100g, respectively. In addition, while antioxidant activity values of leaves of garden orache growing in greenhouse are determined between 8.37% and 30.40%, antioxidant activity values of garden orach leaves growing in field changed between 71.86% and 82.97%. Gallic acid, 3,4-dihydroxy benzoic acid, (+)-catechin and 1,2-dihydroxybenzene were the key phenolic constituents of garden orach leaves growing in garden house and field conditions. In all phenolic compounds studied, gallic acid was determined at the highest ratio, its value changed between 35.64 mg/100g (3rd harvest) and 284.0 mg/100g (1st harvest) for field and 132.81 mg/100g (1st harvest) and 218.0 mg/100g (4th harvest).garden orache leaves are rich in Ca, P, S, Mg, Na and K elements. Calcium contents of leaves harvested from greenhouse and field conditions changed between 12810.5 and 14787 mg/kg to 10623.8 and 15515.3 mg/kg, respectively. In addition, while K contents of leaves harvested from greenhouse vary between 46057.4 mg/kg and 57909.1 mg/kg, K contents of leaves harvested from field changed between 34678.2 and 42214.3 mg/kg.