Relative stability of the silylene-type cyclic compound (HNSi)(3) over (HSiN)(3) has been demonstrated by using correlated ab initio calculations. Aromaticity of both compounds has been revealed by using homodesmic reactions, indicating that Si-II-N building blocks can be used in constructing aromatic species instead of using normal double-bonded (Si-IV=N) systems. Although aromatic stabilization is somewhat smaller for the silylenes than for the Si-IV-N double-bonded systems according to the homodesmic reactions, the total energy of the silylenic compound (HNSi)(3) is lower than that of the silane (HSiN)(3). The stabilization for one silylene unit is the largest for the aromatic cyclic compound (HNSi)(3) among the substituted silylenes.