OBJECTIVE：To desig n and sy nthesize poly （γ-glutamic acid ）-ampelopsin（γ-PGA-AMP），and to characterize it and evaluate its anti-tumor activity in vitro . METHODS ：Synthetic product was produced through an esterification reaction between γ-PGA and ampelopsin. The structure of synthetic product was characterized by the UV spectrophotometry ，Fourier transform infrared（FT-IR）spectroscopy，1H-NMR spectra and the quantitative elemental analysis. The content of ampelopsin in synthetic product was determined by UV absorption spectrometry at 292 nm. Using 5-FU as positive control ，MTT assay was used to determine inhibitory effects of γ-PGA-AMP and ampelopsin on human breast cancer cell MCF- 7，human liver cancer cell HepG 2 and human lung cancer cell A 549. The IC 50 was calculated. RESULTS ：The results showed that the free 7-hydroxyl group of ampelopsin and the a-carboxyl group of γ-polyglutamic acid had been esterified to obtain γ-PGA-AMP；the yield of γ-PGA-AMP was 55.7％，and the content of ampelopsin was 32.3％. The inhibitory effect of γ-PGA-AMP and ampelopsin on MCF- 7，HepG2 and A 549 cells was obvious. IC 50 of γ-PGA-AMP（to 3 above tumor cells ）were 40.19，28.29 and 55.23 μg/mL，those of ampelopsin were 105.30，81.23，130.10 μg/mL，those of 5-FU were 24.72，87.98，30.99 μg/mL，respectively. CONCLUSIONS ：γ-PGA-AMP with anti-tumor effect in vitro is synthesized successfully ，and its anti-tumor effect is stronger than that of ampelopsin.