  First the second-order perturbations of nonzero-\Lambda cosmological models
are derived with an arbitrary potential function of spatial coordinates, using
the nonlinear version of Lifshitz's method in the synchronous gauge. Their
expression is the generalization (to the nonzero-\Lambda case) of second-order
perturbations in the Einstein-de Sitter model which were derived previously by
the present author. Next the second-order temperature anisotropies of Cosmic
Micriwave Background radiation are derived using the gauge-invariant formula
which was given by Mollerach and Matarrese. Moreover the corresponding
perturbations in the Poisson gauge are derived using the second-order gauge
transformations formulated by Bruni et al. In the second-order it is found in
spite of gauges that tensor (gravitational-wave) perturbations and vector
(shear) perturbations without vorticity are induced from the first-order scalar
perturbations. These results will be useful to analyze the nonlinear effect of
local inhomogeneities on Cosmic Microwave Background anisotropies.
