High-resolution ⁴⁰Ar/³⁹Ar dating of Bingchang (BC) eruptions of Changbaishan-Tianchi volcano in NE China yields an oldest plateau age of 137.7 ka, well coinciding with the onset of the Penultimate Deglaciation (PDG). Subsequent eruptions occurred at 132.5-131.7 and 124.2 ka during the PDG and the early phase of the Last Interglacial. The BC tephra in marine sediments from the Japan Sea was deposited during the glacial/interglacial climatic transition. These findings suggest that the BC eruptions were likely triggered by depressurization of the volcano’s magma chamber through mountain glacial melting/retreat during the early phase of the PDG. The peak timing of the Penultimate Glacial Maximum thus derived falls between 142.7-137.7 ka, closely tied to the time of maximum global ice volume/sea level drop at ~140 ka. Since the BC tephra is widely dispersed in marine sediments in the Japan Sea, it will serve as a new well-dated stratigraphic marker for the region.