The researches about reed growth were mainly concentrated on seasonal dynamics, investigation of reed resource, and comparison of different ecotypes of reed. By means of fractal geometric theory of non-linear science, the fractal character of growth patt of reed, for the purpose of quantitatively exploring the mechanism of reed growth was studied. The way to calculate fractal dimension of reed growth is box-dimension (BD) and information dimension (ID). The results shown that the difference between two samplings in May and those among three samplings in June and later were not remarkable for both BD or ID. It was noted that the difference between samplings in and after May is significant. It was demonstrated that the fractal dimension of size distribution of reed ranged from 0.6235 to 0.8761. The distribution patt could be statistically divided as two significant periods:the size of reed is quite well-distributed at the beginning of reed growth (fractal dimension > 0.8), but is irregular in the middle and later growth season (fractal dimension < 0.7). These results are benefit to reach the goal of rational use of reed resources and to protect the biodiversity in wetland ecosystem.