Regulatory T (Treg) cells play a crucial role in immune tolerance, and numerous studies have focused on the molecular mechanisms of CD4+ Treg cells, whereas the role and relevant mechanisms of CD8+ Treg cells remain unclear. Ly49 is located at murine NK and T cells, and plays a similar role to human KIRs in regulation of immune response. In this paper, we have explored the effect of AIM2 deficiency on the homeostasis of CD8+Ly49+ regulatory T (Treg) cells in AIM2 knockout (KO) mouse model. We have performed KLH immunization model for AIM2 KO mice and found enhanced function of suppressive CD8+ Treg cells in the absence of AIM2, indicating AIM2 dampens the homeostasis of murine inhibitory CD8+ Treg cells.