Salt accumulation and ion constitution were studied by investigating greenhouse Gerbera jamesionii cultivation in Fengxian Area of Shanghai City,and analyzing both greenhouse and open field soil samples.The results showed that soil acidification and secondary salinization occurred.Soil acidification was mainly due to the accumulation of NO3-.Apart from HCO3-、K+,the contents of Cl-、SO42-、NO3-、Na+、Mg2+、Ca2+increased to different degree in greenhouse soils and they were well correlated each other. NO3- and Ca2+ were the major ions in the soils.The significant stepwise regression equation between ions and soil salinity is ρ（soil salinity）=0.291+5.295ρ(Ca2+)+2.177ρ(NO3-).