  Massive stars having a CO core of $\sim$40-60 M$_\odot$ experience
pulsational pair-instability (PPI) after carbon-burning. This instability
induces strong pulsations of the whole star and a part of outer envelope is
ejected. We investigate the evolution and mass ejection of metal-poor very
massive stars which experience PPI. We use stellar models with initial masses
of 140, 200, and 250 M$_\odot$ and the metallicity Z=0.004. Their masses
decrease to 54.09, 58.65, and 61.03 M$_\odot$ before the neon-burning owing to
mass-loss and He mass fraction at the surface becomes about 20%. During the PPI
period of $\sim$1-2000 yr, they experience six, four, and three pulsations,
respectively. The larger CO-core model has the longer PPI period and ejects the
larger amount of mass. Since almost all surface He has been lost by the
pulsations, these stars become Type Ic supernovae if they explode. Light curves
during the PPI stage and supernovae are investigated and are implicated in
luminous supernovae. The luminosity created by the interaction of different PPI
ejecta becomes $M_{\rm bol} \sim -16$ to $-20$. The interaction between the
circumstellar shell ejected by PPI and the supernova ejecta can be more
luminous. These luminous transients could be an origin of Type I superluminous
supernovae and supernovae with precursor.
