Unlike white matter composed mostly of neurites, cerebral cortex includes a significant amount of somas from neurons or glial cells besides neurites. Mean kurtosis (MK) of diffusion kurtosis imaging characterizes cortical microstructural complexity contributed by both neurites and somas, but the exact contribution of somas to cortical MK is unknown. Neuronal density plays a vital role in neurodegenerative disorders. Quantitative delineation of the soma compartment is critical for assessment and therapeutic monitoring of soma compartment with noninvasive diffusion MRI. We for the first time proved and quantified soma and neurite compartmental contributions to cerebral cortical MK.