Widely distributed in the Yangtze River mainstream, the riparian wetlands have important ecological functions such as purifying water quality and maintaining biodiversity and are an important material basis for ensuring water ecological security of the Yangtze River Basin. The wetlands in the Yangtze River Basin have received a lot of attention on their distribution pattern, dynamics and ecological significance, while the riparian wetlands in the Yangtze River mainstream, one of their important components, has been less studied and reported. In this study, the distribution pattern of the riparian wetlands in the Yangtze River mainstream is revealed quantitatively by remote sensing images being interpreted. The influences of channel morphology, climatic dryness and wetness, population and socio-economic factors on the formation of the riparian wetland's current distribution pattern are explored and discussed. The results are as follows. The riparian wetlands in the Yangtze River mainstream are fully developed, with 105 riparian wetland patches covering a total area of 6976.19 hm² and occupying a total shoreline length of 377.14 km. Small- and medium-sized riparian wetlands are the most dominant of all size, which is consistent with the tendency that the lower the level of individual area of the riparian wetlands, the larger the scale of the wetlands at the corresponding level measured in terms of total area, total shoreline length and total patch number. The spatial distribution of riparian wetlands in the Yangtze River mainstream shows three sections, namely, the Yibin-Yichang section, where almost no riparian wetland is distributed; the Yichang-Yueyang section, where only small- to medium-sized riparian wetlands are densely distributed; the below-Yueyang section, where dense small- to medium-sized riparian wetlands and few medium- to large-sized wetlands are distributed. Hubei, Anhui, and Jiangsu Province have the largest scale of riparian wetlands. The total scale of the riparian wetlands on the left-bank is higher than that on the right-bank. Individual wetland area is significantly larger under low shoreline curvature and high river width conditions (P≤0.05) and is also larger under low slope and low GDP conditions (0.05≤P≤0.1), indicating that straighter, wider channel and relatively less developed economic are significantly favorable to the development of the riparian wetlands in the Yangtze River mainstream. The development of the riparian wetlands is doubly constrained by the fact that they can be viewed as both "landscapes" and "wetlands" at the same time.