Arabidopsis thaliana is the most widely used model plant in the area of plant biosciences, and the cell line T87 is one of the most commonly used lines in Arabidopsis cell cultures. The characteristics of lignins in cultured cells often differ from those of lignins in intact plants. To date, nothing is known about the lignins of T87 cells. In this study, we characterized lignins of T87 cells using six analytical methods; phloroglucinol staining, thioacidolysis, nitrobenzene oxidation, alkaline hydrolysis, and Klason and acetyl bromide methods. These analyses clearly showed that lignins of T87 cells are composed of guaiacyl and p-hydroxyphenyl units, and are quite different from lignin found in the Arabidopsis inflorescence stem, which is composed of guaiacyl and syringyl units.