The aim of this work is to study the influence of UVC on allelopathic potential of Lupinustermis L (lupine) for various time intervals against metabolites and their biosynthetic enzymes in Portulacaoleracea L.The results indicate that exposure of lupine seedlings to UVC resulted in the increase of total phenols and total flavonoids in lupine leaves. Treatment of P. oleracea seedlings with various irradiated and non-irradiated lupine leaf extracts at various concentrations (20, 40, 60, 80 and µg ml-1)resulted in reduction of total soluble carbohydrate and total soluble protein in a concentration-dependent manner. Also, the treatment enhanced H2O2 content, lipid peroxidation and the activity of NADH-oxidase (EC: 1.7. 99. 4) in P. olercaealeaves. However, the activities of ribulose 1,5-bisphosphate carboxylase (EC: 4.1. 1.39), glyceraldehyde 3-phosphate dehydrogenase (EC: 1.1. 1.8), nitrate reductase (EC: 1.7. 99. 4) and nitrite reductase (EC: 1.7.1.4) were reduced under the same treatment. The impact of allelopathic effect of irradiated lupine leaf extract was more pronounced compared to non-irradiated.