Abstract： Objective To measure the volume of hippoeampal formation(HPF) in healthy Chinese Han adults and provide database for researching on a variety of diseases associated with alteration of hippocampal structure. Methods This is a clinical multi-center study. One thousand Chinese healthy volunteers (age range = 18 to 70) recruited from 15 hospitals were divided into 5 groups, i. e. , Group A (age range = 18 to 30), B (age range =31 to40), C (age range =41 to 50), D (age range=51 to 60),and E (age range =61 to 70). Each group contained 100 males and 100 females. All of the volunteers were scanned by MR using T1 weighted three-dimensional magnetization prepared rapid acquisition gradient echo sequence. The margin of HPF were outlined manually for each side. Using multiple linear regression,relationships between hippocampal volume and sex, age, weight and height were analyzed respectively.Independent two sample t test was used to study the differences between male and female and between lcft and right. The differences of hippoeampal volume among age groups were analyzed by ANOVA. Results Hippocampal volume for left and right side were (4752 ± 659) and (5032 ± 660) mm3 respectively. The volume of HPF is significant correlated with gender and age, but without relevance to height and weight ( left and right r = 0. 283,0. 311, F = 30. 127,37. 050 ,P < 0. 01 ). The volumes of left and right hippocampus were (4897 ± 670), (5192 ± 667)mm3 respectively for men, and (4647 ± 624) and (4904 ± 630) mm3 for women. The right hippocampal volume was larger than the left ( t = 7. 030,6. 696, P < 0. 05 ). On both sides, men have larger hippocampus than that of women ( t = 6. 586,7. 326, P < 0. 01 ). The volumes of the left hippocampus among the five age groups in the male were (4981 ± 684), ( 5003 ± 609 ), (4976 ± 657 ),(4841 ± 631 ), (4631 ± 681 ) mm3 respectively, while the volumes of the right hippoeampus were (5340 ±647) ,(5276 ±582), (5264 ±620), (5133 ±661 ), (4894 ±699) mm3 respectively. Among age groups,the differences were statistically significant ( left and right F = 5. 737,7. 607, P < 0. 01 ). For male, there was significant difference of bilateral hippoeampus between the 18-30, 31-40, 41-50 years group and 61-70 years group ( P < 0. 05 ) and there was no significant difference among the other groups ( P > 0. 05 ).There was no significant difference of hippocampal among different groups in women (P > 0. 05 ).Conclusions With high-resolution MRI, the volume of the HPF was accurately measured, so as to provide the basic data for research of the hippocampus-related disease.