There are some inter-instrument differences in measured values by using self-monitoring of blood glucose (SMBG) devices. The reason is caused by characteristics of comparison method and kind of specimen. ISO issued the International Standard for SMBG devices (ISO 15197: 2003an vitro diagnostic test systems-Requirements for blood-glucose monitoring systems for self-monitoring in managing diabetes mellitus). I this document, the system accuracy evaluation shall be performed with at least 100 fresh capillary blood samples, each with sufficient volume to be measured by two different meters and at least in duplicate by the manufacturer's measurement procedure in this document. Capillary blood samples shall be collected by skin puncture (e.g., fingerstick), prepared and processed according to the instructions for use, including sample pre-treatment if required. Sample containers designed for the collection of capillary blood should be used. Only unaltered capillary blood samples shall be used for glucose concentrations of 2.8-22.2 mmol/l (50-400mg/dl). However, it is difficult to perform in Japan. Then the new calibration procedure instead of the system accuracy evaluation by ISO document is established by using venous whole blood by volunteers. This procedure is possible covered from low concentration level to high concentration level of glucose. It can be applied to calibration of system accuracy.