This study scopes the purification of alkaline phosphatase enzyme extracted from the liver and the investigation of kinetic properties for the reactions with and without inhibitor. Michaelis Menten and Lineweaver Burk graphs were drawn by means of experimental results. K-m and V-max values were calculated from these graphics. According to these values, substrate affinity (K-m) and maximum velocity (V-max) values were determined. Values without inhibitor; K-m=0,047 V-max=24,87; with urea inhibitor K-m=0,054 V-max=20,83; with creatinin inhibitor K-m=0,037 V-max=20,83. The experiments were repeated with inhibitory substance and inhibition type was established. How high blood urea and creatinine levels affected alkaline phosphatase activity were determined. In this study, urea was found to cause noncompetetive inhibition and creatinine to cause uncompetetive inhibition on liver ALP.