The method of evaluating development uniformity in twocomponent development system is proposed. Conventionally, it was known that the arrangement of the magnetic brush has influence on image quality. But there are few experimental approaches to quantification of these factors because of the difficulty of the direct observation at development area. Therefore, we pay our attention to the toner pattern generated on a photoconductor. In this method, a photoconductor, on which a solid pattern is developed previously, is prepared, and next, the sleeve and the photoconductor are settled with an interval of development gap. Then, voltage is applied to remove the toner from the photoconductor. As a result, a toner removed pattern can be obtained on the photoconductor. By analyzing this pattern, carrier contact ratio during the developing time is calculated, and some indexes of development uniformity are proposed. It is possible to evaluate the effects of parameters related to the arrangement of magnetic brush, and parameters related to the number of contact times. The relationship between the development uniformity and graininess is measured and it is shown that the proposed method is effective to estimate the graininess.