Objective: To investigate the possible age- and sex-related differences in the various dimensions of corpus callosum among Chinese normal adults. Methods: Magnetic resonance images of 286 healthy adults

including 127 males and 159 females

and ranging in age from 20 to 81 years

were investigated. They were classified into 5 age groups （ 20–29

30–39

40–49

50–59

and 60–81 years old）. Corresponding to the age group sequence above

the male/female ratio of each group respectively was: 25/26

26/33

33/50

32/36

and 11/14. The following dimensions of corpus callosum were systematically measured on the midsagittal T1-weighted images: frontal to occipital pole （represented as line segment AB）

total longitudinal dimension of the corpus callosum （CD）

the maximum height （EF）

the widths of the genu （CX）

anterior one third （GH）

central region （EZ）

posterior one third （MN） and splenium （YD）. After that

the obtained data was analyzed statistically. Results: （1） The total longitudinal dimension

maximum height

widths of the genu

central region and splenium were proved to be larger in females. But the widths of the anterior one third and posterior one third were similar in-between. In spite of that

a conspicuous sex-related difference was not found. （2） The total longitudinal dimension and the maximum height of the corpus callosum remained stable in all age subgroups. Yet the widths of the genu

anterior one third

central region

posterior one third and splenium had a tendency of decreasing gradually with aging. Statistical difference was seen in the anterior one third

central region

posterior one third （P<0.05）. Conclusion: There is no sex-related difference in all dimensions of corpus callosum. But

with aging

a significant difference is found in the widths of the anterior one third

central region and posterior one third.