Melinjo (Gnetum gnemon L.) seed skin is known to contains phenolic, flavonoid, and resveratrol which could act as antioxidant sources. However melinjo seed skin still has limited usage. This research was aimed to identify the presence of resveratrol and its antioxidant capacity of various part of melinjo peel at different maturity stage. Melinjo seed skin was extracted under maceration using ethanol 96%. Analysis of total phenolic content, total flavonoid content, resveratrol and antioxidant activity are conducted on the obtained crude extracts. The result show that the higher antioxidant activity found on the inner skin of melinjo peel. The highest antioxidant activity obtained from the inner green skin of melinjo with IC50 value 227.1546 ± 37.29 mg/L extract. For the highest total phenolic content was obtained from the inner yellow skin of melinjo 169.1163 ± 2.15 mg TAE / g sample and the highest total flavonoid content found in the outer green skin of melinjo which value 8.3562 ± 0.066 mg QE / g sample. The result from LCMS analysis found that all the three inner skin with different maturity stage (red, yellow, and green) contains resveratrol compounds.