A cellular sliding gate is composed of an inner and outer thin plates having plane rectangular geometry and separated by a combination of horizontal and vertical stiffening plane webs. Cellular sliding gates have strength and stiffness besides their lightweight. The main objective of the present research will be concentrated on the study of the structural behavior and responses of the sliding gate under hydrostatic and wave pressures. The simplified structural method of grillage analysis will be tried. The hydrostatic and the wave pressures distributed to the gate are converted into equivalent nodal forces by lumping. The results of different methods of analysis are compared. The grillage analogy is fast and economical and the output results are found to be acceptable for design and analysis purposes especially in preliminary design and in plane quick analysis.