  Meson-baryon interactions are the fundamental building blocks to study the
structures of baryon resonances and meson properties in few-body nuclear
systems. We review the recent progress in the investigation of the meson-baryon
interaction in the strangeness S=-1 sector and the structure of the
Lambda(1405) resonance. In particular, we present an attempt to construct a
realistic Kbar N-pi Sigma interaction in chiral SU(3) dynamics in response to
the precise measurement of the kaonic hydrogen, and discuss the subthreshold
extrapolation of the Kbar N interaction with the information of the pi Sigma
channel.
