Abstract: Objective To investigate the relationship of corpus callosum area with gender and age. Methods Totally 920 healthy objects with MRI examination were grouped by gender and age, corpus collosum areas (CCa), intracranial areas（ICa）, additionally CCa-ICa ratio (CIR) was measured on mid-sagittal section with SE-T1WI. Statistical analysis, scatter plot and curve fitting between these index and age were completed by SPSS software. Results Mean corpus collosum areas of normal males were larger than that of females (P<0.05), but there was no difference of CCa-ICa ratio for gender (EM>P/EM>>0.05). Significant difference of these index across different age groups was testified by LSD-test (EM>P/EM><0.05), it implied that CCa followed inverted quadratic term-curves across the human lifespan, the optimal equation for CCa(EM>Y/EM>)-ages(EM>X/EM>) was：［EM>Y/EM>=457.346+9.434EM>X/EM>-0.113X2］.Conclusion Significant difference of corpus collosum size with gender and age was clearly demonstrated in our study.It predicts that the changes of corpus collosum size follows an inverted quadratic term-curve acros

Key words: Corpus callosum, Gender, Age, Magnetic resonance imaging, Human