[Objective] The objective of this study is to investigate the influence of water delivery process on diversity of the plants in Qingtu Lake in order to provide basis for functional analysis in this region. [Methods] After a four year locating observation, biodiversity index was applied to analyze plant diversity in Qingtu Lake shores. The relationships between plant diversity variation and underground water level were also investigated. [Results] The number of plant species reduced within 200 m range from the water surface, and the maximum reduction occurred at the surface of water while the minimum reduction occurred at 100 m. Shannon-Weiner, Pielou index and Simpson index showed a similar trend, richness and Shannon-Weiner decreased, while Pielou index and Simpson index increased. Simpson index changed greatly, and the spatial variation was greater than the temporal variation. In contrast, the temporal variation of the Cody index was greater than the spatial variation. [Conclusion] Importing water to Qingtu Lake had prompted the spatial distribution of plant species. The water source is centre for the belt distribution of the plant species, and the change increase with the rise of the underground water level.