Technical Abstract: Due to its potential in preventing or slowing the occurrence of many diseases, resveratrol (3,5,4-trihydroxystilbene) has attracted great research interest. The objective of this study was to identify the microorganisms that possess resveratrol producing capability from selected plants and optimize the conditions for resveratrol production. Endophytes from grape wine Merlot (Vitis vinifera L. cv. Merlot), wild Vitis (Vitis quinquangularis Rehd.), and Japanese knotweed (Polygonum cuspidatum Siebold & Zucc.) were isolated, and the resveratrol-producing isolates were screened. A total of 65 isolates were obtained and 21 produced resveratrol (6 to 123 µg/L) in liquid culture. The resveratrol-producing isolates mainly belonged to seven genera, Botryosphaeria, Penicillium, Cephalosporium, Aspergillus, Geotrichum, Mucor, and Alternaria. The resveratrol production capability was decreased or completely lost in most isolates after subcultured for three times. Only the strain of Alternaria sp. MG1 had a stable and high resveratrol production capability in all subcultures. During liquid cultivation of Alternaria sp. MG1, the synthesis of resveratrol started on the first day, increased to a peak on the 7th day, and then decreased sharply. Cell growth increased during the cultivation and reached a stable and high level of biomass after 5 days. Through optimization using the Response Surface Methodology, the best fermentation conditions for resveratrol production by liquid culture of Alternaria sp. MG1 were an inoculum size of 6 %, medium loading rate of 125 mL in a 250 mL flask, rotation speed of 101 r/min, and temperature of 27 °C. The resveratrol production capability under optimized conditions was 422 ± 8µg/L. This study indicated the existence of resveratrol synthesis pathway and related genes in microorganisms and a potential in producing resveratrol through fermentation with the isolated fungi.