  There are quantum states of light that can be expressed as finite
superpositions of Fock states (FSFS). We demonstrate the nonclassicality of an
arbitrary FSFS by means of its phase space distributions such as the Wigner
function and the $Q$-function. The decoherence of the FSFS is studied by
considering the time evolution of its Wigner function in amplitude decay and
phase damping channels. As examples, we determine the nonclassicality and
decoherence of generalized and reciprocal binomial states.
