  Based on chiral unitary approach, we construct the realistic KbarN local
potential, which is useful for the quantitative calculation of Kbar-nuclei.
Since the resonance pole structure of the KbarN system seems important for the
Kbar-nuclei and the spacial structure of Lambda(1405), we establish the
construction procedure of the local potential paying attention to the
scattering amplitude in the complex energy plane. Furthermore, for the
quantitative study of the Kbar-nuclei, we consider the constraint from the
recent experimental data measured by SIDDHARTA, which significantly reduces the
uncertainty of the KbarN amplitude. With this new local potential, we estimate
the spacial structure of Lambda(1405) and obtain the result indicating the
meson-baryon molecular state of Lambda(1405).
