Abstract: The eleven title compounds are classified into three series according to their molecular structure having mono-, bi- and tri-condensed ring system, respectively. For each series the hydrolytic stabilities decrease with the increase of the calculated CNDO/2 net positive charge on C atom of carbonyl group. This relation supports the kinetic hydrolysis mechanism, in which the hydrolysis reaction is initiated by the nucleophylic attack on the C atom of the carbonyl group. It can be applied to predict the relative stsbility of some cyclourea nitroamines by means of similar theoretically calculated parameters. For bi- and tri-condensed ring compounds, which have V- and U-type optimized configurations respecively, the steric hindrance due to the C=O group covering large —CH_2C(NO_2)_3 group plays an important role also, especially for the V-type bi-condensed ring compounds.