  New results of NA61/SHINE on determination of charged hadron yields in
proton-carbon interactions are presented. They aim to improve predictions of
the neutrino flux in the T2K experiment. The data were recorded using a
secondary-proton beam of 31 GeV/$c$ momentum from CERN SPS which impinges on a
graphite target. To determine the inclusive production cross section for
charged pions, kaons and protons the thin ($0.04\, \lambda_I$) target was
exploited. Results of this measurement are used in the T2K beam simulation
program to reweight hadron yields in the interaction vertex. At the same time,
NA61/SHINE results obtained with the T2K replica target ($1.9\, \lambda_I$)
allow to constrain hadron yields at the surface of the target. It would
correspond to the constraint up to 90% of the neutrino flux, thus reducing
significantly a model dependence of the neutrino beam prediction. All measured
spectra are compared to predictions of hadron production models.
  In addition a status of the analysis of data collected by NA61/SHINE for the
NuMI target (Fermilab) is reviewed. These data will be used further in neutrino
beam calculations for the MINERvA, MINOS(+) and LBNE experiments.
