Abstract: This study used the natural flavonoid compound silybin as the parent compound and synthesized 16 silybin derivatives through oxidative dehydrogenation, alkylation, selective demethylation, and acylation. The structures of these derivatives were confirmed by ¹H NMR, ¹³C NMR, and MS. All derivatives were found to be new compounds never reported in previous literature. Using gastric cancer cell line SGC-7901 and human glioblastoma cell line LN-229, the in vitro anti-tumor activity of the novel silybin derivative was determined through MTT assay with lapatinib as the positive control. The experimental results indicate that the synthesized novel silybin derivatives have a certain degree of anti-proliferative effect on two types of cancer cells, with compounds I2 and I14 showing strong anti-proliferative activity against LN-229 and SGC-7901 cells.