Nowadays, the definite cause of leukemia is still a mystery, certain factors are known to increase the risk of developing the disease like radiations and other factors. There is no way to predict or prevent leukemia. The types of leukemia are grouped by how quickly the disease develops and gets worse. Leukemia is either chronic (gets worse slowly) or acute (gets worse quickly). There is an abundance of evidence that the immune system plays a critical role in the control of (Chronic Myelogenous Leukemia) CML but the exact mechanism of action remains unclear A mathematical model for the human immune systemís response to CML in a hypothetical patient will be proposed with the purpose to help identify promising directions for experimental research on treatments for patients with CML.