Chemical investigation of Jasminum pentaneurum Hand.-Mazz led to the isolation and identification of 12 compounds, which included one new secoiridoid glycoside, 10-(3-hydroxy-4-methoxy-benzoate)-ligustroside (4), three secoiridoid glycosides (1–3), and eight phenols (5–12). All compounds were reported for the first time from this plant. Their structures were elucidated based on extensive spectroscopic data analysis, including HR-ESI-MS, UV, IR, 1 D, and 2 D NMR. The absolute configuration of the new one (4) was further elucidated by comparison of its experimental and calculated quantum chemical electronic circular dichroism (ECD) spectra. All the isolates were assayed for their inhibitory activity on four human cancer cells. Compound 11 exhibited inhibitory effects against three human cancer cells SK-MES-1, SMMC-7721 and SGC-7901 with IC50 values ranging from 83.0 to 172.0 μM.