Abstract: Lithium has two stable isotopes(6Li and 7Li)with nature abundance of 7.52% and 92.48%, respectively. Due to the large mass difference between the two lithium isotopes and low Li contents in geological samples, Li isotope measurements have met large difficulty in the past several decades. High precision Li isotope analytical methods are only developed recently, and three major methods are currently used: (1)TIMS method with analytical precision of