Inspired from the serious plastic deformation of some gears with heavy power transmission in practical usage in metallurgical industry, we believe that there must existed some kind of gear profile which is most suitable in both the contact and bending fatigue strength. The aim of this paper is intention to produce a gearing of these properties. From careful analysis and deep going investigation, we think that it is the profile of equal conjugate curvature with high order of contact, and analyzed the forming principle of this kind profile in mathematic method. The contact stress is so low that even the Hertz theory, with which the contact stress can be calculated for most of gearing, is invalid. This paper researched how to realize this kind of gearing.