Abstract: Phragmites australis is a dominant species in the intertidal zones of the Chongming Dongtan wetland and has good functions in water and soil conservation and purification.P. australis populations mainly distribute at the middle and high tidal flats with zonal pattern, but also distribute at the low tidal flats with small patches. As a typical rhizomatous clonal plant, how P. australis populations will show their dynamic characteristics and adaptive abilities along the different tidal flats is worth studying deeply. In this study, we analyzed the whole growth and developmental processes of the cohorts of P. australis starting from April and June, through location tracking method and analysis on the dynamic life tables, survival curves, survival rates and cumulative mortality rates, so as to reveal the dynamic characteristics of P. australis populations distributing at the three tidal flats. The results show as follows: (1) the survival curves of cohorts starting from April at low, middle and high tidal flats tended to approach the Deevey-Ⅰ type, and transition form of Deevey-Ⅱ type and Deevey-Ⅲ type, and transition form of Deevey-Ⅰ type and Deevey-Ⅱ type; (2) the survival curves of cohorts starting from June at the low and middle tidal flats were similar to April cohorts, while the cohort's survival curve at the high tidal flats changed from the transition form of Deevey-Ⅰ type and Deevey-Ⅱ type to the transition form of Deevey-Ⅱ type and Deevey-Ⅲ type; (3) through the comprehensive analysis, the stability of P. australis populations was the strongest at the high tidal flat, and the most fragile at the low tidal flat, while the populations at the middle tidal flat was unstable at the early growth stage and tended to be stable later; (4) based on the above results, pertinent suggestions were put forward for the conservation and management of P. australis populations distributing along the tidal flat gradient in Dongtan wetland.