目的　通过对正常人海马体积的MRI测量，为与海马体积变化相关疾病的诊治及预后等提供参数值。  方法　选取健康志愿者240例，男性、女性各120例，按照年龄段分为5组，每组男女各24人，用1.5T MRI对所有的受试者行垂直海马长轴的斜冠状位1mm层厚扫描，经过识别、分割，进而计算海马的体积。  结果　（1）不同性别、侧别的海马体积两两比较，海马体积变化与性别、侧别无显著差异(P＞0.05)。（2）男性40岁之前、之后的海马体积左、右侧别及组间比较均无显著差异（P＞0.05），40岁之前、40岁之后的海马同侧别及组间比较有显著差异（P＜0.05）。（3）女性60岁之前、之后的海马体积左、右侧别及组间比较均无显著差异（P＞0.05），60岁之前与60岁之后的海马同侧别及组间比较有显著差异（P＜　0.05）。 （4）男、女性左、右侧海马体积分别在相同组间比较，均无明显差异(P＞0.05)。  结论　男性左右两侧海马体积在40岁之前变化不明显，40岁以后明显萎缩。女性左右侧海马体积在60之前变化不明显，60岁以后明显萎缩。

Objective　Through MRI measurement of the normal hippocampal volume, the image data related with diseases that can change the hippocampal volume changing could be supplied for clinical diagnosis, treatment and prognosis.　Methods　240 cases of healthy volunteers were selected, including 120 men, and 120 women, and divided into five groups  according to age. Each group included 24 men or 24 women.  Line perpendicular to hippocampal long axis of the thin layer of oblique coronal was scanned using 1.5T MRI for all subjects. Then the square and volume of hippocampus were calculated through fine identification and segmentation.　Results  (1) The results suggested that there was no significant difference in the hippocampal volume between different gender, sidesthe  in pair wise comparisons (P> 0.05). (2) there was no significant difference of themale hippocampal volumes of the same side before  and after 40 and among different groups (P>0.05). (3)The female hippocampal volumes of both sides before and after 60 that had not significant difference (P> 0.05).  (4)Hippocampal volumes of left and right sides in male and female did not show obvious difference in parallel groups.　Conclusion　The right and left hippocampal volume in male before 40 years old does not change significantly, however, marked atrophy could be observed after 40 years old; The right and left hippocampal volume does not change significantly before 60 years old in female, while a dramatic drop could be observed after 60 years old.