Phytochemical investigation of the aqueous extract of ~he roots of Agrimania pilosa Ledeb. (Rosaceae), as guided by hepatoprotective activity in vitro, furnished two isocoumarins, agri-monolide (1) and agrimonolide 6-O-$eta$-D-glucoside (3), and (＋)-catechin (2). Compound 1 showed hepatoprotective effects on both tacrine-induced cytotoxicity in human liver-derived Hep G2 cells and tert-butyl hydroperoxide-induced cytotoxicity in rat primary hepatocytes with EC$_{50}$ values of 88.2$pm$2.8 and 37.7$pm$1.6 $mu$M, respectively.y.