Nitrogen Abundant in the air(78 ％),mostly as stable/inactive nitrogen molecules(N2).In the natural system,small portion of nitrogen gas is transformed to chemically active compounds (reactive nitrogen) by lightning,bacterial activities and burning of fuels (Natural fixation of nitrogen).In the past centuny,in order to support the rapid growth of papulation,industrial synthesis of ammonia from nitrogen gas was invented and developed,resulting in introduction of larger amount of reactive nitrogen to natural systems (industrial fixation).Increasing reactive nitrogen in atmosphere,lithosphere,hydrosphere and anthroposphere has built up serious problems of nitrogen-based deterioration of ecosystems and human health.