Two new oligostilbenes, caragasinins D and E, along with four known compounds, kobophenol A, α‐viniferin, wistin, and 5‐hydroxy‐2‐[(4‐hydroxyphenyl)acetyl]‐3‐methoxybenzoic acid, were isolated from the roots of Caragana sinica. These compounds were spectroscopically analyzed for their structures and configurations and compared with existing data. The configurations of caragasinins D and E were elucidated by 1H‐NMR spectroscopy, CD spectroscopy, and time‐dependent density‐functional theory simulated ECD spectral data. All six compounds were evaluated for their inhibitory activity against neuraminidase (NA) from Clostridium perfringens. Among the tested compounds, 5‐hydroxy‐2‐[(4‐hydroxyphenyl)acetyl]‐3‐methoxybenzoic acid demonstrated statistically significant NA inhibitory activity, which was comparable to the positive control, mangiferin.