Chamaecrista rotundifolia (C. rotundifolia) is a perennial herb of leguminosae, which increasingly being grown as a forage in China. In our search for original bioactive metabolites from Cassia plants, the phytochemical reinvestigation of the C. rotundifolia was carried out, which led to the isolation of three new (1-3) and six known (4-9) chromones. Their structures were confirmed by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1-9 were evaluated for their anti-rotavirus activities, and the results revealed that compounds 1-9 exhibited potential anti-rotavirus activities with therapeutic index (TI) valves in the range of 12.0~20.2, respectively.