Carbon nuclear magnetic resonance ( 13 C NMR) methods for determining the composition of cis-/trans-and positional isomers in hydrogenated vegetable oils were developed to reduce analytical time. By selecting appropriate olefinic carbon peaks and by measuring individual peak areas subsequent to the identification of isomeric peaks on the NMR spectrum, compositional results of the isomers coincided well with those obtained by conventional gas chromatography (GC). Therefore, it is highly beneficial to choose the 13 C NMR method when analysis time is limited. Though the proposed 13 C NMR method is promising, further development is needed. For the time being, combination with the traditional GC method is still encouraged for precise compositional analysis of cis-/trans-and positional isomers. JAOCS 75, 801-805 (1998).