Background：Cardiotoxicity has been one of the most common causes for withdrawing drugs from the market, and its important manifestation is the prolongation of QT interval. Iptakalim hydrochloride (ITKL) is a selective ATP-sensitive potassium (KATP) channel opener, it is crucial to assess the risk of cardiac repolarization of ITKL in clinical trials. Objective: This study was conducted to determine the effect of ITKL on corrected QT (QTc) interval. Method: A randomized, double-blind, placebo-controlled, single- and multi-dose regimen was carried out to investigate the QTc and ITKL concentration correlation. ITKL was administered at doses of 5 mg, 10mg, 15mg, and 20mg with single oral administration and 10 mg, 20 mg with multiple oral administration, along with placebo, in 83 healthy subjects. Electrocardiograms (ECGs) and blood samples were collected on a preset time schedule. Result: The highest dose (20mg) of ITKL did not cause QTc prolongation with a predicted ΔΔQTcF (Baseline and placebo-corrected QTc interval) effect under geometric Cmax of 1.67 milliseconds, meeting the criteria for negative effect on QT. The Exposure Response (ER) analysis indicated the effect of the drug on ΔΔQTcF was relatively small. Conclusion: The upper bounds of the 90% confidence interval (CI) of the model-predicted ΔΔQTcF at Cmax in all dose groups were bellow 10ms, suggesting that ITKL did not prolong QT interval.