A conjugate of poly(y-glutamic acid)(y-PGA) with 5-fluorouracil (5-FU) (y-poly(a-hydroxymethyl-5-fluorouracil-glutamate)), y-PFUG, was prepared as a polymeric prodrug matrix. The release of 5-FU and the degradation behavior of y-PFUG, which is soluble in polar organic solvents were studied. y-PFUG films were prepared by casting from DMF. The y-PFUG matrix degraded in 7 days and incorporated 5-FU was released in 3 days. 5-FU release was accelerated by mixing free 5-FU into y-PFUG. Here, y-PFUG functioned as a hydrophobic degradable matrix. Analogous with y-PFUG, y-PGA conjugated with a drug may be useful as a biodegradable polymeric prodrug.