Presupernova evolution and explosive nucleosynthesis in massive stars
for main-sequence masses from 13 M. to 70 M. are calculated. We examin
e the dependence of the supernova yields on the stellar mass, C-12(alp
ha, gamma)O-16 rate, and explosion energy. The supernova yields integr
ated over the initial mass function are compared with the solar abunda
nces.