CD8+ T cells are key members of adaptive immunity against tumorigenesis. As subset of CD8+ T cells, effector T cells (Te) and memory T cells (Tm) have different biological activities. The former can kill tumor cells but come into apoptosis in a certain period and the latter is static with the ability of self-renewal. Previous studies showed that microRNAs (miRNA) played critical roles in regulating adaptive immunity. This study aimed to identify the different expression of miRNAs between Te and Tm cells in tumor-bearing mice and to sort out the target miRNAs which can be regulated to improve anti-tumor activities of CD8+ T cells.