Abstract: Chlorpyrifos (CPF) is an organophosphorus pesticide most widely used all over the world.With environmental durability and bio-accumulation, CPF enters human body through water, food, living environment, and even ambient air and distributes into blood and saliva.CPF could affect nervous, immune, reproductive, and endocrine system, and even affect the growth of a fetus.CPF could induce acute poisoning symptoms by cholinergic toxic effect.In addition, CPF could cause genetic toxicity, such as DNA damage, gene mutation, and chromosome aberration, inducing cell canceration and increasing the risk of lung cancer and leukemia.Due to disturbing immune system and changing levels of endocrine hormones such as sex and thyroid hormone, CPF could affect gametes function, interfere with embryo formation and evolution, and lead to a series of birth defects and diseases.In the case of exposure to CPF during the early stage of brain development, CPF could have long term effects on structure and function of nervous system and even increase the risk of neurodegenerative disease.Therefore, the reduction of CPF use and exposure is of great significance for health maintenance of human beings.