Abstract: The paper presentes a design and implementation solution of the marine hydrostatic calculation and stability criteria. The system normally contains three subsystems such as data input, kernel computation and results displays. For the system implementation, Sybase was used as the background database to store the input data and the results of calculation, and VB. NET was selected as the development platform for the coding. B-spline algorithm, the basic and kernel of the system was discussed. The presented system has an excellent characteristic, obtaining offsets from ship design file of AutoCAD format intelligently, which alleviates the annoying, burdensome input work of system users.