In this paper we used Cox- Regression model as the best model to analysis data, and applied to patient with Leukemia in Iraq. The data which is used in this research was taken from the Medical city Hospital in Baghdad includes (62) patient during (1/5-1/9 ).we estimated models parameter by using (partial likelihood) method and then test the models parameter by using (Wald test) and the result shown that the variables (treatment type) and (address) has the effect on survival time. And we used (Likelihood ratio test) it was shown that the model which contains tow variables (treatment, address) is the best model to study.