Tumor-inhibiting experiment in vivo and tumor_cell_killing experiment in vitro were carried out in mice for Cortex Moutan Radicis, Caulis Lonicerae and Herba Lycopi.The results showed that the tumor_inhibiting rate of Cortex Moutan Radicis was over 50%,IC 50 38.403 mg/L,and its 95% confidence limit in 31.19 ～ 47.29 mg/L. The tumor_inhibiting rate of Caulis Lonicerae was more than 30%,IC 50 7.306 mg/L and its 95% confidence limit in 4.56 - 11.71 mg/L.The tumor_inhibiting rate of Herba Lycobi was less than 30%,IC 50 18.11 mg/L and its 95% confidence limit in 11.23 ～ 29.20 mg/L.It is suggested that Cortex Moutan Radicis,Caulis Lonicerae have certain antineoplastic effect.