ABSTRACT This study aims to assess the tannin gradation extracted from the bark of pine and mahogany tree. Tannin content was analyzed using the permanganometric titration method and was identified using gas chromatography-mass spectrometry. The results show that pine and mahogany bark consist of three and four layers, respectively. The secondary phloem of pine locates in the deepest layer, while its periderm locates in the first and second outermost layers. The secondary phloem of mahogany locates in the first and second innermost layers, while its periderm locates in the first and second outermost layers. It is found that higher in vertical position of bark on the tree, the smaller in amount of tannin could be extracted, both on pine and mahogany tree. However, the outer layer of both pine and mahogany barks provides lower tannin content. It could be suggested from this study that tannin from pine bark should be extracted from the layer near the cambium, meanwhile tannin from mahogany bark should be extracted from the middle layer of the bark. Thus, large amounts of tannin from living tree bark could be obtained without damaging the tree's physiology or inhibiting tree growth.