Background: Euonymus japonicus is one species of celastraceous family used as a decorative plant and in traditional Chinese medicine. The lack of information about the main active constituents and the possible biological activities of Iraqi Euonymus japonicus leaves is considered a motivation to start this in vitro study

Objectives: to identify the phytochemical components and to evaluate antioxidant and antimicrobial activities

 Material and Methods: The chemical composition of Iraqi Euonymus japonicus leaves was identified and analyzed using the Reversed-Phase High-Performance Liquid Chromatography approach and the antioxidant properties were measured by free radical - scavenging assay DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate). Furthermore, the antibacterial properties were evaluated via the agar well diffusion method against two pathogenic bacteria Staphylococcus- aureus, E. coli, and Candida albicans.

Results: The results showed that the main active constituents of Euonymus japonicus leaves in ethyl acetate fraction were Naringenin, vitexin, Kaempferol, Apigenin, and quercetin respectively.in addition,  antioxidant activity    ethyl-acetate fraction had the greatest antioxidant activity with the IC50 value of 54.89 μg /mL while the highest antimicrobial efficacy of the ethyl acetate extract (3.125, 6.25, 12.5, 25, 50, and 100 µg/ml) was demonstrated by the inhibitory zones (12-19 mm for Staphylococcus- aureus,16-20 mm for E. coli,16-21 mm for candida albicans) compared with positive control Augmentin (19 mm) and ketoconazole (16mm) respectively

Conclusion:   The first identification of antimicrobial and antioxidant activity of E. japonicus in vitro, show this plant has the highest activity compared to standard, this activity is related to the polyphenolic compound.