Five hydroxystilbene derivatives were synthesized and their structures were determined using high-resolution mass spectrometry, 1H NMR, and IR. In this study, the antioxidant activities of eight hydroxystilbenes(five synthesized hydroxystilbene derivatives and three other compounds) were evaluated with the free radical scavenging model 1,1-diphenyl-2-picrylhydrazyl. It was observed that there exists a very significant linear relationship between the reciprocal of the EC50 value of each of the compounds and the maximum wavelength of the ultraviolet absorption peaks. It is believed that this result will be helpful for the further synthesis of such antioxidants.