In the locked condition of a oneway clutch, high stress will be generated at the contact surfaces between rollers or sprags and the races of the inner and outer wheelings. A study on the characteristics of self-locking can not go without regard for the effect of the deformation caused by these stresses in each part of the clutch. In this study a unique way to derive mapping functions has been developed and each part of the clutch has been analysed by using the two-dimensional theory of elasticity. Furthermore, on the reflection of the contact surfaces, the behavior of the sprag which rotates under the locked condition is analysed here by using the finite element method.