Abstract The magnetic properties of lithium ferrite nanocrystallites ranging from 9.1 to 860 nm have been studied. The specific saturation magnetization σs of these nanocrystallites decrease lineally with the nanocrystallite size.The specific magnetization versus temperature curves (T) and M?ssbauer spectra of sample A (diameter D = 860 nm), sample B (D = 11.8 nm) and sample C (D = 9.1 nm) have been measured. It is found that the Curie temperatures of samples B and C are 50℃ lower than that of sample A. From the σ(T) curve of sample C, it seems that sample C consists of two magnetic phases. These phenomena have been discussed with the superparamagnetism and the surface magnetism of sample C.