Abstract: In order to investigate the motion of the center of mass of liquid in a turning tank truck, tanks with four common section shapes, i.e., circular, oval, multi-section arc and square, are considered in this research. The liquid in the tank is assumed to be quasi-static during the turning. The liquid center of mass is calculated through the integration of the center of mass for each homogeneous section plane. Using MATLAB, the centroid coordinates and centroid trajectory images are obtained. The lateral stability characteristics of tank trucks with different shape of cross-section is analyzed. The research results provide guidelines for the design and driving stability of liquid tank truck.