In this study, Nitrate Reductase Activity (NRA) in different organs (leaf, shoot and flowers-fruits) of 14 shrub species [Arbutus unedo L. (Ericaceac), Paliurus spina-christi Miller (Rhamnaceae), Pistacia terebinthus L. (Anacardiaceae), Quercus cerris L., Q. coccifera L., Q. robur L., Q. trojana TB. Vebb. (Fagaceae),Jasminum fruticans L., Phillyrea latifolia L. Olea europeae L. (Oleaceae), Cistus creticus, C. laurifolius (Cistaceae), Pyrus amygdaliformis (Rosaceae), Ailanthus altissima Miller (Simaroubaceae)] was investigated. The significant differences were found among shrub species according to examined plant organs (P < 0.05). Although NRA was high in leaves of many species, nitrate assimilation properties of Mediterranean shrubs was specific to species. The highest NRA was found in the leaves of Paliurus spina-christi (2.74 +/- 0.60 mmol NO(3)(-) g(KM)(-1). saat(-1)) whereas it was found in the generative organs of Jasminum fruticans (1.53 +/- 0.32 mmol NO(2)(-) g(KM)(-1). saat(-1)). The significant positive correlation was not found between leaf NRA and actuel NO(3)(-) in surrounding soils (P > 0.05). But it was found between other plant compartments (shoots and generative orgnas) and actual NO(3)(-) content in the soils (P < 0.05).