Abstract: To synthesize the folic acid-alliinase conjugate(FA-Alliinase), and to study its targeting and antitumor activity on cervical cancer HeLa cells. FA-Alliinase I and FA-Alliinase II were synthesized by two methods. The couping ratios of two conjugates measured were 12 and 31, respectively. The FA-Alliinase II with high coupling ratio was selected and its structure was characterized preliminarily. The activity of alliinase retained about 50% in FA-Alliinase II determined by HPLC. The specific effect of FA-Alliinase II on HeLa cells was observed by confocal laser and flow cytometry. The antitumor activity of conjugate combined with alliin was determined by MTT, and IC₅₀ of alliin was(127. 6±2. 3)μmol/L. This study provides a direct evaluation method for the synthesis and optimization of FA-Alliinase.