  It is important to properly describe the mass-loss rate of AGB stars, in
order to understand their evolution from the AGB to PN phase. The primary goal
of this study is to investigate the influence of metallicity on the mass-loss
rate, under well determined luminosities.
  The luminosity of the star is a crucial parameter for the radiative driven
stellar wind. Many efforts have been invested to constrain the AGB mass-loss
rate, but most of the previous studies use Galactic objects, which have poorly
known distances, thus their luminosities. To overcome this problem, we have
studied mass loss from AGB stars in the Galaxies of the Local Group. The
distance to the stars have been independently measured, thus AGB stars in these
galaxies are ideal for understanding the mass-loss rate. Moreover, these
galaxies have a lower metallicity than the Milky Way, providing an ideal target
to study the influence of metallicity on the mass-loss rate.
  We report our analysis of mass loss, using the Spitzer Space Telescope and
the Herschel Space Observatory. We will discuss the influence of AGB mass-loss
on stellar evolution, and explore AGB and PN contribution to the lifecycle of
matter in galaxies.
