This study, for the first time, investigated the relationships of miRNA polymorphisms involving in insulin signaling pathways and T2DM, and reported that miR-133a-2 rs13040413, let-7a-1 rs13293512, and miR-27a rs895819 were related to the susceptibility to T2DM in overall or stratified analyses in a Chinese population. Here, INS is linked to type 2 diabetes mellitus.