We determined the anatomical geometry and thicknesses distribution of the triceps surae aponeuroses from anatomical observation of a human cadaver. Geometry of the aponeuroses was examined by two dimensional photoanalysis. The thicknesses of slices dissected from various regions of the aponeuroses were measured with digital microscope. The results of quantified geometry and thickness of the aponeuroses suggest that the portions frequently experiencing large forces, such as the aponeuroses at the insertion of the posterior soleus and origin of anterior soleus, possess thicker tissues. This quantitative information may contribute to biomechanical simulation and modeling to reveal the function of the muscle aponeurosis-tendon complex, and development of realistic simulation models would facilitate surgical and treatment design.