Optimum conditions for liver arginase in rabbit and distribution in the tissues was investigated. In the study, the tissues of six one-year-old New Zealand rabbits were used. Its was found that preincubation temperature 65 °C, preincubation period 13 minutes, incubation period 10 minutes and optimum pH 10 for arginase in rabbit liver tissue. Enzyme achieved its highest activity at 2 mM MnCl₂ concentration. Km of arginase in rabbit liver tissue for L-arginine were measured to be 1.6 mM. Consequently, it was determined that Mn⁺² ions and preincubation at 65 °C were essential for the activation of the enzyme. Among liver, kidney, heart, uterus, brain, spleen, intestine, esophagus, muscle, tongue, lung, stomach, trachea samples, the highest arginase activity was found in the liver and the lowest arginase activity was found in trachea.