We report the discovery of a UHE gamma-ray source, LHAASO J2108+5157, by analyzing the LHAASO-KM2A data of 308.33 live days. Significant excess of gamma-ray induced showers is observed in both energy bands of 25-100 TeV and \gt100 TeV with 9.5 sigma and 8.5 sigma, respectively. This source is not significantly... Show more