Recent studies demonstrate that organic nitrogen is a significant pool of atmospheric nitrogen (N).It occurs in precipitation by incorporating gas phase materials or by scavenging of aerosols.Organic nitrogen existence in aerosol phase is linked either to gas to particle conversion of gaseous precursors like organic nitrates or to species existing in aerosol phase like amino acids or to multiphase reactions.Earlier studies have shown that N deposition can significantly influence the seawater productivity in the oligotrophic Eastern Mediterranean sea.This work presents the results of N speciation in wet deposition and aerosol size segregated samples collected in the E.Mediterranean during two and one year periods respectively.