In this study, we selected the reed (Phragmites australis) of typical lakewetland in Yinchuan to explore the monthly change characteristics of the growth index of reed, established the prediction model of the relationship between reed biological characteristics and analyzed the main soil factors affecting the growth of reed in habitat, which provides a theoretical basis for the ecological restoration of lakewetland and the effective management of reed wetland. The main conclusions are as follows: (1) the growth rate of reed was fast in Yinchuan lakewetland from May to July (P＜0.05) and the growth rate slowed down from August to September(P＞0.05). The peak value of plant height, coverage and biomass appeared in August or September, and the biological indexes in October showed changes in the ups and downs (P＞0.05). (2) In Yinchuan lakewetland, the density of reed increased, the community environment changed, and the living space of individual plant was reduced, which inhibited the lateral growth of stem, and the density was negatively correlated with stem diameter (P＜0.01). Leaf area per plant increased, leaf area per plant also significantly increased along with the increase of biomass and plant biomass in aboveground biomass(P＜0.01). (3) The relationship between plant height and aboveground biomass can be expressed by the power function model or the exponential function model. The positive correlation between the plant height and the aboveground biomass in the early growth stage showed a positive correlation and then decreased with the growth rate. The aboveground biomass of JuneAugust stem diameter increased with the increase of aboveground biomass, and the stem lateral growth has played a role of physical support. Morphological and biomass indices were best fitted in the peak period(August or September), which were all power function models, which showed allometric relationship. (4)Soil total nitrogen (TN), soil organic carbon (SOC), soil available nitrogen (AN), total salt, pH and available potassium (AK) were the characteristic factors affecting the growth of reed, and the effect of TN and SOC was the greatest on the growth of reed.