Abstract: Arginase is a key enzyme of ammonia metabolism in human,which takes part in many important physiological processes and plays a crucial role in the development of cancer.In recent years,the relationship between arginase and tumor has become a hot research.It has been proved that arginase has a special guiding significance in diagnosis and treatment of the colorectal cancer.This passage will give a brief review about arginase in the current research progress and its research status in the colorectal cancer.