Effect of Uracil’s derivatives on enzyme glutamate oxaloacetate transaminase (GOT) for sample of normal human and some types of leukemia patients, acute lymphatic(ALL) (11 cases), acute mylosyticl (AML) (4 cases), acute mylomonocyticl (AMOL) (2cases), acute pro- mylocyticl (APL) (3 cases), chronic mylobid (CM) (4 cases) and chronic lymphatic (CLL) (4 cases) is investigated. The ages of patients are between (10-69 years). Some synthesized derivatives of uracil were used as an inhibitors and a comparison between the activity of (GOT) in the presence and absence of inhibitors for two-types of serums under the same conditions is studied. The percentage of inhibition and type of inhibition is also included in this study, which was showed degree of inhibitions in normal individuals between (31% - 73%) and degree of inhibitions in patient’s individuals between (25% - 80%) which showed that inhibition was significantly higher in the sera of patient with leukemia. The activity was determined colorimetrically by Retiman and Frankel method.