Polymer-drugs composite with long periods of controlled slow release was made by radiation induced polymerization in room temperature. In experiment in vivo, the composite were implanted subcutaneously the back of rabbits. The concentration of 1- (2-tetrahydrofuryl) -5-fluorouracil (FT-207) was determined by HPLC. The results of test showed that the concentration of serum drug is 1.0,µ,g/mL after 1 week in the polymer-drug composites group. The drug concentration of tissue surrouding the composites is 76.2±10.4,µ,g/mL. The drug concentration in the far organ (e.g.the lung 1.2±0.5,µ,g/mL) is lower than the tissue surrounding the composite. The serum drug is higher and shorter time by the routine methods. The serum concentration of FT-207 is lower and retarded by implanted.