Mercury sphygmomanometer (MSM) is reliable and widely used in clinics and hospitals. The principle of Korotkoff sounds method (KSM) applied in the MSM is also a gold standard to measure blood pressure. Many efforts have been made attempting to replace MSM, which is criticized for being not healthy and safe. In this research, an electronic blood pressure monitor, named K-sounds electronic sphygmomanometer (KESM), was designed as a substitute to MSM. The three key elements of KSM were proposed for the first time. We used appropriate electronic components to build the KESM which can fulfill the functions related to the three key elements. The KESM, which was easy to operate and free of mercury, followed the same principle as MSM. The same principle guaranteed the comparable accuracy. We took equivalence test and the results showed that the designed KESM was as accurate as the calibrated standard MSM. The designed KESM passed the certifications of SFDA and is qualified in clinics or hospitals for diagnostic purposes. Mercury sphygmomanometer (MSM) is reliable and widely used in clinics and hospitals. The principle of Korotkoff sounds method (KSM) applied in the MSM is also a gold standard to measure blood pressure. Many efforts have been attempted to replace MSM, which is In this research, an electronic blood pressure monitor, named K-sounds electronic sphygmomanometer (KESM), was designed as a substitute to MSM. The three key elements of KSM were proposed for the first time. We used appropriate electronic components to build the KESM which can fulfill the functions related to the three key elements. The KESM, which was easy to operate and free of mercury, followed the same principle as MSM. equivalence test and the results showed that the designed KESM was as accurate as the calibrated standard MSM. The designed KESM passed the certifications of SFDA and is qualified in clinics or hospit als for diagnostic purposes.