With a simple and high-yield production method, a zinc-containing sustained-release composition capable of stabilizing a physiologically active protein or peptide, typically G-CSF by precipitation and retaining drug efficacy for several days in a living body owing to its sustained releasability is provided. Concretely, a zinc-containing sustained-release composition produced by forming a precipitate by mixing a physiologically active protein or peptide, a water-soluble zinc salt, a water-soluble carbonate and/or a water soluble phosphate aqueous solution. The zinc-containing sustained-release composition may be administered as a zinc-containing sustained preparation by adding a pharmaceutically acceptable additive as is necessary.