〔Abstract〕 Objective To study the miR-1285 through Yes-associated protein 1(YAP1) on the proliferation, apoptosis and mechanism of chronic myelogenous leukemia K562 cells. Methods The plasmid of miR-1285 was constructed to make K562 cells overexpress miR-1285 and knock down miR-1285. They were divided into four groups: miR-1285 mimics, mimics control, miR-1285 inhibitor, and inhibitor control; qRT-PCR was used to quantitatively analyze the expression of miR-1285 of these four groups. The expression level of miR-1285 in the group was used to verify the transfection efficiency. The apoptosis and proliferation of the four groups were detected by CCK-8 and Annexin V-FITC; the changes of YAP and its downstream molecule epidermal growth factor receptor(EGFR) were detected by Western blot, and apoptosis related molecules BAX, Bcl-2 protein expression was detected. Results After knock down miR-1285, it can promote the proliferation of K562 cells and inhibit apoptosis. The expression of YAP increased, the expression of downstream molecule EGFR increased correspondingly, the expression of apoptosis-related molecule BAX decreased, and the expression of Bcl-2 increased; After expressing miR-1285, K562 cell proliferation decreased, apoptosis increased, YAP expression decreased, downstream molecule P-EGFR expression decreased, apoptosis molecule BAX expression increased, and Bcl-2 expression decreased. Conclusion miR-1285 can inhibit the proliferation and promote apoptosis of K562 cells of chronic myelogenous leukemia by inhibiting the expression of YAP. It is expected to become a targeted molecule for the treatment of chronic myelogenous leukemia.