In order to realize the performance of the mechanical structures, it is fundamentally important to show the sufficient level of the safety. However, it is rather difficult to show the degree of safety quantitatively. There are many uncertainties in the operation of mechanical quipments and so it is difficult to show the degree of safety quantitatively. In the mechanical field, the safety factor is widely used as the measure of the safety in design stage. Usually, the safety factor is determined by some experience and not by clear scientific basis. To promote the reliability based design in mechanical field, it is extremely important to develop reliability related standards. In the activities of JSME Material and Mechanics Division, we investigated the technical back ground of reliability based design and some reports have been already published. Since the development of reliability related standard is extremely important, we are planning to issue reliability based JIS standard. The details of background, technical basis and future plan will be shown in the presentation.