By sampling a unit area and using methods such as counting and measuring, a comparative study was performed on the quantitative characteristics of the ramet module of Phragmites australis populations in four habitats in the Zhalong Wetland National Reserve. The results showed that the P. australis populations in the four habitats turned green around May 10 and began to enter the vegetative growth period. The height and density of the ramets continued to increase until the beginning of the reproductive growth period in August, and a significant difference was observed between June and August (P < 0.05). The difference was not significant from August to October (P > 0.05). When the P. australis populations entered the reproductive growth period, the ramets stopped growing in height, and at the same time, the output of the underground bud no longer formed ramets to increase realistic population. The biomass of the ramets and population continued to increase until the beginning of the exuberant reproductive growth period in September, and it decreased when entering the dormant period in October. The difference between each month was significant. At the end of the growing season, P. australis populations showed characteristics such as distributing and transferring the material produced underground for storage as well as contributing to the formation and growth of vegetative reproductive organs. There was a significant logarithmic correlation between the quantitative characteristics of P. australis and the actual growth time after returning green. The goodness of fit of equation was 0.818-0.994, and the fitting equation reached a significant level of P < 0.05. The density of ramets was the highest in the wet habitat, followed by the aquatic habitat and xeric habitat; it was the lowest in the saline-alkali habitat. The height and biomass of the ramets and population were the highest in the aquatic habitat, followed by the wet habitat and xeric habitat; it was the lowest in the saline-alkali habitat. Therefore, the quantitative characteristics of the ramets of the P. australis populations in the four habitats showed a basically consistent rhythm in the growth period. Individual growth and population dynamics of the P. australis populations showed obvious environmental effects, and moisture and pH were the main factors that affected the quantitative characteristics of the ramets of the P. australis populations in the Zhalong Wetland National Reserve.