  We evaluated the uncertainty relevant to s-process nucleosynthesis using a
Monte-Carlo centred approach. We are based on a realistic and general
prescription of temperature dependent uncertainty for the reactions. We
considered massive stars for the weak s-process and AGB stars for the main
s-process. We found that the adopted uncertainty for (n,$\gamma$) rates, tens
of per cent on average, affect the production of s-process nuclei along the
$\beta$-stability line, while for $\beta$-decay, for which contributions from
excited states enhances the uncertainty, has the strongest impact on branching
points.
