A uniquely shaped ink ingot was unearthed from Tomb M10 of the Eastern Han Dynasty in the Dongjiang cemetery. Such cultural relics are rarely found in tombs of the same period and therefore it holds important research value. To determine its material, ultra depth-of-field microscopy, field emission scanning electron microscopy, Fourier transform infrared spectrometry, and pyrolysis gas chromatography-mass spectrometry were employed, and the results were compared with modern oil-soot ink and pine-soot ink. The findings show that the micro-appearance of the sample closely resembled that of pine-soot ink. Its FTIR spectrum showed the telescopic vibration absorption peak of the C=C bond in the aromatic ring skeleton, while its ion chromatogram revealed a series of polycyclic aromatic hydrocarbons and pyrolysis compounds characteristic of pine wood, such as retene and methyl dehydroabietate. These results confirm that the material was pine soot ink. Further observation and analysis suggest that the ink ingot was hand-molded, with a form resembled those of “garlic” and “flower” from cultural relics of the same period.