Objective To determine the medical practice value of fractional anisotropy (FA) in neonatal brain injury. Methods 32 infants with HIE (including mild group in 6, moderate group in 5, control group in 15 and suspected group in 6) were studied. Each group was examined with conventional MR imaging and diffusion-tensor MR imaging to analyze FA value in regions of interest. Results Conventional MR imaging results: the mild group, moderate group and control group adjust to clinical diagnosis, the suspecd group haven’t detect abnormal signal. FA values in mild group and moderate group were significantly lower than in control group (PA<0.05). There were no statistically differences between mild group and moderate group (P<0.05). FA values of two patients in suspected group ranged between mild group and moderate group, while FA values of other four patients in suspected group were not statistically significant. Two neonates in suspected group wee confirmed as neonatal brain injury. Conclusion FA values can be obtained as an objective basis for neonatal brain injury early diagnosis.