  We examine the local density environments around 67 quasars at $z\sim3$, by
combining the imaging data of Hyper Suprime-Cam Subaru Strategic Program
(HSC-SSP) and Canada-France-Hawaii Telescope Large Area U-band Survey (CLAUDS)
over about 20 deg$^{2}$. Our measurements exploit $U$-dropout galaxies in the
vicinities of quasars taken from Sloan Digital Sky Survey (SDSS). We find that
the quasars have the indistinguishable surrounding density distribution from
the $U$-dropout galaxies, and that three quasars are associated with
protocluster candidates within a projected separation of 3 arcmin. According to
a halo evolutionary model, our results suggest that quasars at this epoch
occupy haloes with a typical mass of $1.3^{+1.4}_{-0.9} \times 10^{13} h^{-1}
\mathrm{M_{\odot}}$. We also investigate the dependence of the local galaxy
overdensity on ultraviolet (UV) luminosities, black hole (BH) masses, and
proximity zone sizes of the quasars, but no statistically-significant
correlation was found. Finally, we find that the local density of faint
$U$-dropout galaxies are lower than that of bright $U$-dropout galaxies within
a projected distance of $0.51\pm0.05$ physical Mpc, where the quasar UV
radiation is 30 times intenser than backgroung UV radiation. We argue that
photoevaporation may suppress galaxy formation at short distances where the
quasar UV intensity is strong, even in massive haloes.
