  Using two volume-limited Main galaxy samples of the Sloan Digital Sky Survey
Data Release 10 (SDSS DR10), I investigate the environmental dependence of
galaxy age, and get the same conclusions in two volume-limited Main galaxy
samples: old galaxies exist preferentially in the densest regions of the
universe, while young galaxies are located preferentially in low density
regions. Such an age-density relation is likely a combination of a strong
age-stellar mass relation and the stellar mass-density relation.
