Abstract: Alzheimer's disease (AD) is the most common type of dementia.Mild cognitive impairment (MCI) is considered as a preclinical stage of AD.We studied the MR images of 21 early AD patients,22 MCI patients and 20 normal controls with 3D texture analysis.Texture features of the hippocampus were extracted from the gray level co-occurrence matrix and run length matrix.These parameters including energy (ENG),entropy (ETP),grey level nonuniformity (GLN) and run length nonuniformity (RLN) were significantly different among three groups.Meanwhile,the correlations between parameters and MMSE were calculated,which are widely used in clinical applications.The groups were distinguished based on support vector machines (SVM).Results show that the texture features above are significantly different among three groups,and they are correlated with MMSE scores.The classification accuracy for AD and NC groups is 85.37% (sensitivity and specificity are 90.48% and 80%,respectively).3D texture analysis can reflect the pathological changes of hippocampus in patients with early AD,and can be helpful for early diagnosis of AD.