Red supergiants (RSGs) are massive Population I stars, the major progenitor of supernovae. With strong stellar wind, RSGs are an important source of interstellar dust, in particularly for the high redshift galaxies in the early universe when low-mass stars have not evolved to the asymptotic giant branch phase. However, the estimation of contribution of RSGs to interstellar dust suffers large uncertainty mainly because there is no complete sample of RSGs in any galaxy. This talk will present our recent work on building a complete sample of RSGs in fourteen galaxies of the Local Group using a novel method based on the near-infrared color-color diagram to remove the foreground dwarf stars for relatively distant galaxy. Meanwhile, the Gaia astrometric information is taken as the criteria for the nearby Magellanic Clouds. The sample is almost complete for about 12 galaxies, though Sextans A and B are too far for the UKIRT observation to cover the faint end of RSGs there. The talk will also discuss the potential use of the RSG sample in investigating the stellar model for massive stars and the galactic stellar populations.