  The Crystal Ball Collaboration has recently reported the differential cross
sections and $\Lambda$ polarization for the reaction $K^-p\rightarrow
\pi^0\Lambda$ using an incident $K^-$ beam with momenta between 514 and 750
MeV/$c$. We make a partial wave analysis for this process with an effective
Lagrangian approach and study the properties of some $\Sigma$ resonances around
this energy range. With the inclusion of the 4-star resonances $\Sigma(1189)$,
$\Sigma^*(1385)$, $\Sigma(1670){3\over 2}^-$, $\Sigma(1775){5\over 2}^-$, as
well as a $\Sigma(1635){1\over 2}^+$, which is compatible with the 3-star
$\Sigma(1660){1\over 2}^+$ in PDG, our results can well reproduce the
experimental data. The parameters on the $\Sigma$ resonances and related
couplings are studied.
