The correlation between growth and population distribution of Phragmites australis and soil moisture and electrical conductivity were investigated using Pearson correlative analysis.The result presented that spatial variation of EC_H is obvious,the maximum of EC_H is two times of the minimum.When EC_H is higher than 110 mS/m,pH is higher than 10,Phragmites australis change from single population to mixture population(Phragmites australis Puccinellia distans).Percentage of Puccinellia distans in mixture community increase with increasing EC_H and pH.Population coverage,mean height,fresh biomass and dry biomass are correlated with soil electrical conductivity,their Pearson correlation coefficients are-0.598,-0.567,-0.714,-0.617,respectively.So soil salinity is important impact factor for Phragmites australis population.Soil moisture is significant correlation with coverage and biomass in 10 cm depth of soil profile(p<0.05).Soil moisture is significant correlation with coverage,mean height and biomass in 100 cm depth of soil profile(p<0.05).So soil moisture of surface layer and deep-layer soil profile are very important for Phragmites australis population growth.