Recently, in precision working, precision is in submicron. Therefore, when we measure various finished goods in superfine measurement, because it is relatively difficult to disregard effect of surroundings, these effect of surroundings must be compensated or canceled. In this study, for roundness measurement, three point method is researched which is able to cancel the effect of rotation accuracy of axis and eccenricity of workpiece. It is difference between this three point method and tradi- tional three point method whose measuring apparatus have three movable pickups posit- ioned with angle and between the pickups. As a results, when rotation accuracy of axis is varied from $0.02mu extrm{m}$ to $0.05mu extrm{m}$ the width of variation of measured roundness is $0.04mu extrm{m}$. And, when eccentricity of workpiece is varied from 0 to $4mu extrm{m}$, the width of variation of measured roundness is $0.005mu extrm{m}$. These error width are disregardable because they are in 10% of measured roundness. Therefore, by this three point method, the effect of rotation accuracy of axis and the effect of eccentricity of workpiece are canceled. And we are able to select the angle between the pickups ($phi$ and $ au$) by means of relation between $F_{k}$ and K.