With the rapid growth in technical evolution, medical field is growing like anything. For making good sound we need cooperation from both hands. In this manner, now a day’s medical and engineering technology, both are joined together and developing new innovations in medical field. These innovations are enlightening the life of human by providing proper treatment. Medical field reached a tremendous place in diagnosing tumors after the discovery of CT and MRI. Recent bioengineering researchers involved in medical image segmentation algorithms to speed up the physician’s diagnostic process. Tumor segmentation from magnetic resonance imaging (MRI) data is an important but time consuming manual task performed by medical experts. The various existing automated brain tumor segmentation processes are being described here. Also, one existing segmentation algorithm is implemented to segment the tumor region and to calculate its area based on morphological operation.