The abnormal increase in white blood cells is considered as Leukemia or blood cancer. There are many conventional methods to detect and count the blood cancer cells. But when the accuracy is considered automated method gives far better accepted results than compared to conventional methods. Image processing is one of the widely accepted automated processes for counting the blood cells. The images of the blood samples can be captured using high resolution Webcam connected to light microscope. Further processing can be done using MATLAB based image processing tools. Using this method the counting of cells can be done automatically and accurately.