The drs gene is an apoptosis-inducing tumor suppressor. Previously, we showed that drs contributes to the suppression of tumor formation by generating drs-knockout mice. In this study, by using drs KO mouse embryonic fibroblasts, we found that drs is involved in the autophagy regulation under low serum culture conditions. Both electron microscopy and GFP-LC3 analyses demonstrated that drs is involved in the maturation process of autophagy from autophagosomes to autolysosomes. In addition, drs could associate with Rab24 and the association between drs and Rab24 was enhanced during autophagy. Drs was also co-localized with Rab24 on punctuated structures during autophagy.