  Combining the constraints coming from the ~$M_W$ ~measurements and the
unsuccesful search for the Higgs boson at LEP we determine in the framework of
MSSM the allowed mass regions for the lighter scalar partner of the top quark.
For a heavy top quark particularily strong bounds are obtained for low values
of ~$\tan\beta\equiv v_2/v_1$ ~and light bottom squark.
