In the present study hydroalcoholic extract of oxalis corniculata L and its fraction were evaluated for their phytoconstituents and for their in vitro antioxidant activities. phytochemical screening, these fractions show the presence of flavonoids, phenolic compounds and phytosterols and triterpenoids. In the phytochemical screening, these fractions show the presence of flavonoids, phenolic compounds and phytosterols and triterpenoids. The in vitro antioxidant activity of these compounds may be attributed to flavonoids and phenolic constituents. Based on the above results it may be concluded that the n-butanol fraction and its subfractions possess significant free radical scavenging.