  The oblique parameters $S$ and $T$ are studied in electroweak theory with two
massless Higgs doublets. The effect of quadratic dependence on the charged
Higgs mass in the parameter $T$ could be cancelled. %when mass differences
between the charged and neutral scalars %become large. The constraint on the
charged Higgs mass from the parameter $T$ is not so stringent as it was
expected. The parameter $S$ can be both positive and negative but it can't take
large negative value. We search allowed scalar mass regions for both $S$ and
$T$ in the case of two different reference points.
