Isolation, identification, and antibactery test of triterpenoid compounds from n- hexane extract of tempuyung leaves ( Sonchus arvensis L.) has been done. Maceration from 700 gram of dried leaves powder tempuyung with ethanol and then was partitioned by liquid-liquid extraction with n -hexane condensed n -hexane extracts was 4 gram. Phytochemical test result using Liebermann-Burchard showed that the n -hexane extract contained positive triterpenoid. Separation of n -hexane extract by column chromatography generated positive isolates of triterpenoid in E fraction and obtained triterpenoid isolates as grams. Identification results of triterpenoid isolates from FT-IR spectrophotometer showed C=O ester, -CH 3 , -CH 2 , and C-O ester functional groups whereas identification results from GC-MS showed triterpenoid with molecular mass 552 g/mol and was suspected as pentacyclic triterpenoid ester. Antibactery test results showed MIC values of 50 ppm for ethanol extract, n -hexane extract, E fraction and triterpenoid isolates against E. coli and .