Abstract: In this paper sodium norcantharidate (Na₂NC) was chosen as model drug and sodium norcantharidate albumin microspheres(Na₂NC AM) was prepared by an optimal procedure. The embedding nature, appearance, morphology, size and size distribution, release characteristics in vitro, freeze—drying, ⁶⁰Co radiosterilization and stability of Na₂NC AM were tested. The results showed that the mean size was 0.43±0.12 μm, embedding concentration was 20.34～26. 75 μg/mg, embedding ratio was 21.9～26.4%, release characteristics in vitro was in accord with Higuchi equation. Freeze—drying and ⁶⁰Co radiosterilization showed no influence on Na₂NC AM. The stability of Na₂NC AM was good after 3 months storage.