One new 3,24-dinor-2,4- seco -ursane triterpene, rosanortriterpene C ( 1 ), together with four known compounds including 24-norursane-type nortriterpenes ( 2 – 3 ), 24-noroleanane-type nortriterpene ( 4 ), ursane-type triterpene ( 5 ), was isolated from the fruits of Rosa laevigata var. leiocapus . The new structure was elucidated through comprehensive spectroscopic analysis, including one dimensional (1D) and 2D NMR data, as well as electrospray ionization high resolution (HR-ESI) MS and IR spectrometry. Compounds 1 – 5 showed moderate anti-inflammatory activities against the production of nitric oxide (NO) in RAW264.7 cells stimulated by lipopolysaccharide (LPS) with IC₅₀ values of 10.35 ± 0.92, 14.28 ± 1.20, 5.04 ± 1.43, 29.29 ± 3.64, and 14.37 ± 0.59 µM, respectively.