Abstract: Polyunsaturated fatty acids (PUFAs),especially n-6 and n-3 PUFAs,are not only the body's essential nutrients,but also play an important role in the regulation and prevention of human diseases.n-6 and n-3 PUFAs can not convert mutually in mammalian cells,having different physiological functions.The composition of polyunsaturated fatty acids in cell membranes is determined largely by diets,so balancing the ratio of n-6/n-3 PUFAs is very significant.This article summarizes the metabolic pathways and mechanisms of n-6 and n-3 PUFAs,and combines clinical trials,elaborating the importance of a balanced n-6/n-3 PUFAs ratio.

Key words: PUFAs, n-6/n-3 ratio, inflammation, regulation