Poly-alpha,beta-(3-hydroxypropyl)-DL-aspartamide (PHPA) was synthesized by the ring-open reaction of polysuccinimide (PSI) and 3-hydroxypropylamine. The polymer was characterized by H-1-NMR, C-13-NMR, FTIR, and GPC. Mark-Houwink coefficients were obtained from viscometry and GPC measurements, K = 5.53 x 10(-3) and a = 0.78 in water. The acute toxicity of PHPA was examined and it revealed no death in ICR mice up to the dose treated of 15.3 kg/kg, and hematological parameters showed no significant difference between treated and control animals. The potential use of PHPA as a drug carrier was also investigated. In a typical case, a contraceptive drug, norethindrone (NET), was bonded to PHPA, and the drug sustained released as long as 120 days an in vitro test.