  We investigate the relation between star formation rate (SFR) and stellar
mass ($M_*$) in sub-galactic ($\sim 1$kpc) scale of 93 local ($0.01<z<0.02$)
massive ($M_*>10^{10.5}M_{\odot}$) spiral galaxies. To derive
spatially-resolved SFR and stellar mass, we perform so-called pixel-to-pixel
SED fitting, which fits an observed spatially-resolved multiband SED with a
library of model SEDs using Bayesian statistics approach. We use 2 bands (FUV
and NUV) and 5 bands ($u$, $g$, $r$, $i$, and $z$) imaging data from Galaxy
Evolution Explorer (GALEX) and Sloan Digital Sky Survey (SDSS), respectively.
We find a tight nearly linear relation between the local surface density of SFR
($\Sigma_{\rm{SFR}}$) and stellar mass ($\Sigma_{*}$) which has flattening in
high $\Sigma_{*}$. The near linear relation between $\Sigma_{*}$ and
$\Sigma_{\rm SFR}$ suggests constant sSFR throughout the galaxies, and the
scatter of the relation is directly related to that of sSFR. Therefore, we
analyse the variation of sSFR in various scales. More massive galaxies on
average have lower sSFR throughout them than less massive galaxies. We also
find that barred galaxies have lower sSFR in a core region than non-barred
galaxies. However, in the outside region, sSFR of barred and non-barred
galaxies are similar and lead to the similar total sSFR.
