In this study, the body segment parameters of Koreans were estimated using two-dimensional CT images of cadavers. A software instrument was developed in this study for the image analyses. The software converts 2D images into 3D images and reconstructs the full-body image to automatically distinguish and divide it into fat, bone, and muscle tissues, depending on the body components. The body segments were manually separated by joints, and the software automatically calculated the average mass, volume, and center of gravity of the body segment, and the results were used to analyze the relationship between the body segments and the body characteristics and to build a regression model with statistical significance. The regression model can estimate the mass and volume of segments based on the gender, height, and weight. The software instrument was able to rapidly analyze full-body CT images, and it allows users to easily repeat the analysis.