Objective: The fatty acid components from the rhizome of Rodgersia aesculifolia which were produced in Liuba of the Qinling-Daba mountains in Shaanxi province. Method: The contents and chemical compositions of the fatty acids in rhizome of R. aesculifolia have been investigated and determined in this paper. Fatty oil was extracted with petroleum ether. The oil was determined by GC-MS after the preparation of the methyl esters with BF3-CH3-OH. Result: The experimental results showed that there were 24 components of fatty acids in the oil of R. aesculifolia by GC-MS. There are linoleic acid(41.539%)

α-linolenic acid(23.191%)

pamitic acid(18.824%)

stearic acid(3.408%)

erucic acid(1.506%)

oleic acid(1.388%) and nervonic acid(1.036%). The unsaturated fatty acids accounted for 70.314%. Conclusion: The exepriment reveals were some impotent fatty acids in R. aesculifolia. These results provide theoretical basis for chemical constituent research of R. aesculifolia and future extent research.