This study attempted to investigate the antioxidant properties of four different species of sand dune plants (Calystegia soldanella, Messerschmidia sibirica, Vitex rotundifolia and Rosa rugosa). In order to validate the antioxidant activity of these plants, we first determined the total amount of flavonoid versus phenolic contents (TFC/TPC) and extracted crude flavonoids for measuring antioxidant activities that were determined by DPPH, ABTS and FRAP assays with radical scavenging effects. We found that highest amounts of TPC were detected in R. rugose with values of 110.20 ㎎/g (leaves) and 65.71 ㎎/g (stems), while the highest amounts of TFC in V. rotundifolia with values of 38.07 ㎎/g (leaves) and 6.55 ㎎/g (stems). We further examined how closely related the amounts of TFC/TPC in antioxidant activities and found that R. rugose has the highest activities of radical scavenging with values of 63.4 ㎍/㎖ and 51.2 ㎍/㎖ determined by DPPH and ABTS assays compared with the value of 21.2 ㎍/㎖ by FRAP assay. It is of note that there is a statistically significant correlation between the resulting antioxidant activities and the total ratio of TFC and TPC, suggesting that the different amounts of TFC/TPC may directly contribute to the various antioxidant activities.