Abstract: The influence of wear of grinding wheel on the accuracy of contour grinding and the basic principle and methods of it's compensation are discussed in this paper. In contour grinding, compensation for the wear of the wheel may be performed axially and/or radially. In Radial Compensating, the Nonnormal Compensation Error S may be estimated by formulaδ=△R（1-cosγ）One of the methods for decreasing the error is to limit the wear △R, but more effective method is to limit the Compensation Angle γ, and the most effective method for eliminating the error is Normal Compensation: in this case, because the angle , the errorδequals zero theoretically.Two types of Normal Compensating device designed and experimented with success by the author ate presented: the "Electro-Conducting Roller" and the" Eccentric Crank". Both devices are capable of self-finding the Normal from the contour of the Master during grinding.