Studying the relationship between plants and the environment through plant functional traits is of help to reveal plants' adaptation strategies. At present, most researches on the relationship between plant functional traits and environmental factors have mainly focused on the terrestrial ecosystems. Very few similar studies have been carried out in the riparian ecosystems. Riparian vegetation is a prerequisite for riparian ecosystems to function properly, while maintaining healthy watercourse and landscape connectivity. Therefore, our study selected 10 plant functional trait indices and 14 soil physiochemical property indices to explore plant community functional traits, soil factor characteristics and interaction mechanisms of three habitat types (natural riparian zone (NRZ), farming riparian zone (FRZ) and building riparian zone (BRZ)) within the riparian zones of downtown Chongqing. The results showed that:(1) compared with the NRZ habitat, the soil available phosphorus, available potassium and redox potential in the FRZ habitat and the soil moisture in the BRZ habitat were significantly higher (P<0.05). The soil pH value and total phosphorus content were significantly higher in FRZ and BRZ habitats, while soil organic matter, total potassium and total nitrogen content were significantly lower (P<0.05). (2) In comparison to the NRZ habitats, the specific root length and specific root surface area in the FRZ habitats were significantly higher, and the stem dry matter content and leaf dry matter content were significantly lower. Only the stem dry matter content was significantly lower in the BRZ habitats (P<0.05). (3) The results of redundancy analysis showed that the soil factors which affected the functional traits of riparian plant communities in different habitat types were different. For the NRZ habitats, the influencing factors were soil bulk density, soil moisture and nitrate nitrogen. For the FRZ habitats, the influencing factors were soil ammonium nitrogen, total phosphorus and organic matter. For the BRZ habitats, the influencing factors were soil moisture, soil temperature, and available phosphorus. This study found that in comparison to the natural riparian state, the anthropogenic disturbance of agriculture and structural engineering related projects led to changes in the riparian habitats of downtown Chongqing, and that the plant community improved its adaptability to various habitats through trade-off combinations of functional traits.