Abstract: A simple and isocratic liquid chromatographic using UV detection at wavelength of 425 nm have been validated and used for quantitative analysis of curcumin in ethanolic extract of turmeric (Curcuma longa Linn.) and Curcuma xanthorriza (Zingiberaceae), indigenous to Java region, Indonesia. The method was optimized for separation of three curcuminoids namely curcumin, demethoxycurcumin and bisdemethoxycurcumin using Waters Xterra MS C18 column (4.6×250 mm, 5 μm). The mobile phase used consisted of aquabidestilata and acetonitrile (65:35 v/v) containing 1% acetic acid. The analytical method was validated in terms of linearity, sensitivity, precision and accuracy. The developed method was linear over the curcumin concentration range of 10-60 μg mL–1 with correlation coefficient value of 0.999. The precision of the developed method expressed as Relative Standard Deviation (RSD) value was in the range of 0.17-1.17% for three different levels of sample. The recoveries obtained for the accuracy assessment were 8.50-101.23%. The sensitivity of analytical method was expressed with Limit of Detection (LoD) and Limit of Quantification (LoQ). The values of LoD and LoQ were 1.13 and 3.34 μg mL–1, respectively. The method was successfully used for quantitative analysis of curcumin in the rhizomes of Curcuma longa and Curcuma xanthorriza. The levels of curcumin found in those rhizomes are in the range of 3.03±0.01-7.31±0.02 (C. longa) and in the range of 1.69±0.02-4.92±0.01 (C. xanthorriza).