Objective：This study aims to investigate the effect of PI3K/Akt pathway on the regulation of large conductance Ca2+-activated K+ channel（BK channel）in diabetic coronary smooth muscle cells. Methods： Human coronary artery smooth muscle cells（HCASMC） were incubated with different concentrations of glucose（5 mmol/Land 15 mmol/L），reactive oxygen species（ROS） inhibitor GKT137831 and PI3K inhibitor wortmannin. Streptozotocin-induced diabetic rats were established successfully by intraperitoneal injection. Expression of DNA-Pkcs，Akt，p-Akt（S473）， BK-α subunit and BK-β1 subunits were determined by Western blot. ROS generation in HCASMC was measured in terms of fluorescence using the cell-permeable fluorogenic probe DCFH-DA. Results： Compared with that of HCASMC incubated in 5 mmon/L glucose concentration，the expression of DNA-Pkcs，Akt，p-Akt（S473） increased significantly and BK-β1 subunit decreased significantly（P < 0.05）. Compared with the control group，the expression of p-Akt（s473）decreased significantly（P < 0.05） and BK-β1 increased significantly （P < 0.05） after pretreated with Wortmannin. Conclusion：PI3K/Akt channel is involved in the regulation of BK channel expression in diabetic coronary smooth muscle cells.