Arginase is a key enzyme in the urea cycle, existing in two forms: Arginase I and II, expressed in the liver and various tissues such as the kidneys and brain, responsible for converting arginine into urea and ornithine. The activity of these enzymes is regulated by multiple factors, involving various biological processes outside the urea cycle, such as immune regulation, cell proliferation, and nitric oxide synthesis. Aberrant activity of Arginase is associated with various diseases including liver disease, cancer, and cardiovascular diseases. Studies on the expression and mutations of the Arginase gene reveal its significant roles in physiology and pathology, offering potential targets for the treatment of related diseases.