Atmospheric deposition is an important source of nutrients to many ecosystems. Among the major ecosystems of the biosphere mangrove forests covers about 60 to 75% of tropical coasts. Mangrove productivity is influenced by numerous processes ranging from phytoplankton community succession to global biogeochemical cycles. Atmospheric deposition of nitrogen (AD-N) is a significant source of nitrogen enrichment to estuarine and coastal waters downwind of anthropogenic emissions. Atmospheric deposition, which includes both precipitation (wet deposition and dry deposition) of aerosols and gases, can stimulate productivity by providing macronutrients as well as trace metals. In the North Pacific, it has been noted that 40%–70% of nitrate is derived from terrestrial aerosol sources. Monsoonal variability, from complete failure, to greater than average rainfall, over seasonal and inter-annual timescales, can have profound impacts on primary productivity in waters surrounding mangroves. The deposition flux during Asian dry season and reverine supply and rain deposition during wet season both could be important factors for enhancing phytoplankton production in the land-ocean boundary of Sundarban, This present study focused on simple and cost effective approaches to collect and measurement of atmospheric deposition (dry and wet) in adverse and difficult field condition in Sundarban. In this present study atmospheric deposition was collected seasonally as aerosol and rain deposition in monsoon. Nitrogen content in both samples was estimated by Ion chromatography. Physiochemical parameter, nutrient concentration and primary productivity of the estuarine water also estimated to observe the correlation with atmospheric deposition to explain the contribution of atmospheric deposition in the nitrogen budget in ecosystem.