  We investigate a model of $SU(2) \otimes U(1)$ singlet scalars coupled to
Standard Model. We point out that for the case of maximal mixing between
singlet scalars and standard Higgs boson the Higgs boson production cross
section is smaller than the standard Higgs boson production by factor
$\frac{1}{N+1}$, where N is the number of singlet scalar scalars. For the case
of big mixing Higgs boson could be nonobservable at LHC. However, there is also
a possibility for the observation of scalar singlets at LHC. As a
quasirealistic example we discuss a supersymmetric $SU(2) \otimes U(1)$
electroweak model with an additional gauge singlet chiral superfield.

High Energy Physics - Phenomenology