Mitosis number of tumor cells is an important factor for pathological examinations. Therefore, to get diagnostic information about tumor cells calculating the number of mitosis cells, first of all, it is photographed tumor cells using light microscopy. Number of mitotic cells determined using image processing methods. Aim of the feature extraction for mitosis cell, entropy value, maximum and minimum axis length, area of convex, pixel values, equivdiameter length, area, overlap area parameters are used to define mitosis cells and number of mitosis cells calculated automatically. As a results, for the identification of mitosis cells an algorithm was constituted taking in the consideration mitosis phases using features above mentioned and number of mitosis cells was determined directly. ©2010 IEEE.