  With analyzing the solar system abundance, we have found two universal
scaling laws concerning the p- and s-nuclei. They indicate that the
gamma-process in supernova (SN) explosions is the most promising origin of the
p-nuclei that has been discussed with many possible nuclear reactions and sites
for about fifty years. In addition the scalings provide new concepts: an
universality of the gamma-process and a new nuclear cosmochronometer. We have
carried out gamma-process nucleosynthesis calculations for typical
core-collapse SN explosion models and the results satisfy the observed
scalings.
