In the present study, to examine the potential molecular mechanism of miR-203a expression in CML cells, we constructed double luciferase reporter gene vectors, performed rescue assays, and used biological information software prediction to confirm that miR-203a negatively regulated the expression of WT1, BMI1, and XIAP, which affected the proliferation of K562 cells. Here, BMI1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.