A chemical decomposition of polyurea (PUA) by hydrolysis under high pressure of carbon dioxide (CO2) was proposed. The hydrolysis of PUA was carried out at 190 A degrees C for 2 h under 7.0 MPa of CO2 in the presence of water. The hydrolysis reaction gave white residual solid and water soluble compound. The white residual solid was characterized to be degraded PUA by FT-IR spectrum and elemental analysis. H-1-NMR spectra of the water soluble compound revealed that the hydrolysis of PUA produced diamine only from repeating unit of PUA, which was a component of PUA. This hydrolysis gave the corresponding diamine for quantitative yields.