  We investigate lepton flavor violating (LFV) radiative processes and the
relic abundance of neutralino dark matter in supersymmetric type-I seesaw
model. We carefully derive threshold corrections to the flavor off-diagonal
elements of slepton mass matrix and up-type Higgs mass squared and find that
they can be large in the case of large $B_N^0$. We examine how the branching
ratios of LFV radiative decays and the relic abundance of neutralino dark
matter can be significantly affected by the large threshold corrections. Soft
scalar mass squared parameter of up-type Higgs scalar is also affected by the
threshold corrections. Since the higgsino mass depends on the mass parameter
for up-type Higgs, the LFV processes and the relic abundance of the neutralino
dark matter are correlated with each other. We show that there are parameter
regions where the predictions of the relic abundance of neutralino dark matter
are consistent with WMAP observation and the branching ratios of LFV radiative
decays are predicted to be testable in future experiments. We find that the
masses of scalar supersymmetric particles are not necessarily small so that the
branching ratios of LFV decays can be testable in future experiment, which is
distinctive feature of this scenario.
