The aim of this study was to investigate the possibility utilizing Metasequoia(Metasequoia glyptostroboides) cone as a new natural dye resource. Dyeing onto cotton fiber was carried out to study the effect of dyeing conditions and mordanting effect on dye uptake, color change, and colorfastness. FT-IR analysis supported that hydrolyzable tannins were contained in the extracted colorant. Metasequoia cone colorant showed low affinity to cotton fiber and maximum dye uptake was obtained at pH 3.5 showing YR Munsell color. Mordanting improved dye uptake regardless of mordant type, especially Fe(C5H10FeO6) mordant was effective as much as 2 times higher dye uptake comparing with un-mordanted sample. The color of dyed fabric with mordanting showed YR Munsell color except of the Fe(FeSO4·7H2O) mordanted sample showing Y Munsell color. Colorfastness to rubbing and washing was relatively good, whereas lightfastness of the dyed fabrics was above grade 3/4 except that the dyed samples with Fe mordanting showed grade 2. It is necessary to apply Metasequoia cone colorant onto other fibers, especially protein fibers, for evaluating its efficacy as a new natural dye resource.