Blood pressure is defined as the amount of force at unit area which the blood exerts on a wall of a blood vessel. The BP has a clinical importance as the basic index in the medical examination of patients. Especially, the percentage of the hypertensive is more than 15% in an adult population of Korea and hypertension is notorious as 'a silent killer' because it has no prior symptoms. The most important thing in the diagnosis, treatment and prognosis of hypertension is the accurate measurement of the BP. In this study, we developed the blood pressure simulator for the monitoring of oscillometric BP devices and compared this KRISS simulator with commercial simulators. Finally, we tested the commercial oscillometric BP devices (6 models from 5 manufacturers) using the KRISS simulator. The KRISS simulator has the repeatability error below 0.1% for the pressure generation and we expected to develop the BP simulator for Korean by the collection of clinical data from Koreans.