Soluble forms of neutral peptide-hydrolases (protaminsulphate as a substrate) of the cat cerebral hemisphere grey and white matter were investigated by the method of gel-filtration on Sephadex G-150. The results of the experiments showed that grey and white matter of the cerebral hemispheres contains different forms of soluble neutral peptide-hydrolases. The products of protaminsulphate hydrolysis were analyzed by the method of gel-filtration as well (Sephadex G-25). Under the influence of the studied enzymes of protaminsulphate hydrolysis occurs due to subsequent splitting of C-terminal residues of arginine. It means that the studied soluble neutral peptide-hydrolases of grey and white matter of the cat cerebral hemisphere may be referred to the group of exopeptidases.