Two new stilbenes, 5-methoxy-6-(4-methoxystyryl)-3-methylbenzofuran (1) and 5-methoxy-6-(4- hydroxystyryl)-3-methylbenzofuran (2), together with six known ones, bauhiniastatin D (3), gramideoxybenzoin B (4), gramistilbenoid A (5), gramistilbenoid B (6), gramniphenol H (7), and pterostilbene (8), were isolated from the whole plants of Arundina graminifolia. Their structures were established by their 1D, 2D NMR, and MS spectral data. Compounds 1 and 2 were tested for their anti-SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) activity. The results revealed that compound 1 exhibited potential activity with IC50 of 17.4 μM for delta strain and 28.5 μM for Omicron BA.1 strain, compound 2 also showed potential activity with IC50 of 15.3 μM for delta strain and 22.6 μM for Omicron BA.1 strain, respectively.