  We discuss the environmental dependence of galaxy evolution based on deep
panoramic imaging of two distant clusters taken with Suprime-Cam as part of the
PISCES project. By combining with the SDSS data as a local counterpart for
comparison, we construct a large sample of galaxies that spans wide ranges in
environment, time, and stellar mass (or luminosity). We find that colours of
galaxies, especially those of faint galaxies ($M_V>M_V^*+1$), change from blue
to red at a break density as we go to denser regions. Based on local and global
densities of galaxies, we classify three environments: field, groups, and
clusters. We show that the cluster colour-magnitude relation is already built
at $z=0.83$. In contrast to this, the bright-end of the field colour-magnitude
relation has been vigorously built all the way down to the present-day and the
build-up at the faint-end has not started yet. A possible interpretation of
these results is that galaxies evolve in the 'down-sizing' fashion. That is,
massive galaxies complete their star formation first and the truncation of star
formation is propagated to smaller objects as time progresses. This trend is
likely to depend on environment since the build-up of the colour-magnitude
relation is delayed in lower-density environments. Therefore, we may suggest
that the evolution of galaxies took place earliest in massive galaxies and in
high density regions, and it is delayed in less massive galaxies and in lower
density regions.
