One new triterpene compound, 3beta-acetoxylup-20(30)-en-29-al and two known 3-acetylptiloepoxide and 3beta-acetoxylup-20(29)-ene were isolated for the first time from the leaves of Campanula lactiflora and their structures were deduced by high field 1D and 2D 400 MHz NMR, EI-MS and (+) LC-MS/MS spectra.