  Oxygen to iron abundance ratios of metal-poor stars provide information on
nucleosynthesis yields from massive stars which end in Type II supernova
explosions. Using a standard model of chemical evolution of the Galaxy we have
reproduced the solar neighborhood abundance data and estimated the oxygen and
iron yields of genuine SN II origin. The estimated yields are compared with the
theoretical yields to derive the relation between the lower and upper mass
limits in each generation of stars and the IMF slope. Independently of this
relation, we furthermore derive the relation between the lower mass limit and
the IMF slope from the stellar mass to light ratio in the solar neighborhood.
These independent relations unambiguously determine the upper mass limit of
$m_u=50 \pm 10 M_sun$ and the IMF slope index of 1.3 - 1.6 above 1 M_sun. This
upper mass limit corresponds to the mass beyond which stars end as black holes
without ejecting processed matter into the interstellar medium. We also find
that the IMF slope index below 0.5 M_sun cannot be much shallower than 0.8.
