摘要:Synthetic dye waste of textile industry has contaminated the water and aquatic living organism. One of the solution is used teak leaves as the natural dye. Common conventional extraction process is soxhletation which need more time and more solvent. One of extraction method that has been developed is ultrasound assisted extraction (UAE). The objectives of this research were to study the effect of solvent, extraction time, pH, and extraction yield. The conclusion of this research was optimum yield of teak leaves extract about 42,79% at pH 3 and extraction time of 20 minutes with aquadest as the solvent using UAE method. If natural dye of taek leaves was used on cotton, the color will change depend on fixator that was added. In GC-MS analysis, some compound that were detected are decanoic acid methyl ester and methyl tetradecanoate. Both of the compound have chromophore cluster.