Abstract: MicroRNAs are endogenously expressed non-coding RNAs, which are composed of approximately 18 nucleotides to 25 nucleotides. Mature microRNAs regulate gene expression by base pairing with the 3'-untranslated region of target mRNAs. These mature microRNAs can degrade target mRNAs or inhibit translation. This process is a type of post-transcriptional regulation of gene expression. Studies have shown that microRNAs are important in physiological and pathological processes, such as cell proliferation, cell differentiation, and cell death. This article provides an overview of the function of microRNAs in the regulation of macrophages.