A new angular dihydropyrancoumarin named wulongensin A, along with five known coumarins, (-)-anomalin, umbelliferone, (-)-smyrinol, 3'(S),4'(S)-disenecioyloxy-3',4'-dihydroseselin, (+)-trans-khellactone, was isolated from the root of Peucedanum wulongense. The structure of wulongensin A was established as 3'(R)-angeloyloxy-4'(R)-isovaleryloxy-3',4'-dihydroseselin by spectroscopic methods and the absolute configurations were deduced by chemical correlations with known compounds.