In this thesis we consider the general method for calculation the normal pressure tensor for confined fluid in nano slit pores. This equation is a general form of normal pressure tensor for any fluid (with different inter molecular confined in a slit pore with different fluid- wall interaction). As a first try we have solved this equation for hard sphere fluid confined between two parallel structures less hard walls. Our result shows the oscillatory form of normal pressure tensor versus distance of the walls. This oscillation has function as density and when the density decreased the height and depth of the oscillation is reduced. Also the result shows that when the distance between two walls increased the functionalized of pressure versus z is vanished and the value of the pressure is equal to macroscopic pressure and it is so interesting that the vdw like equation may be derived for normal pressure. For furthermore studies about confined fluid in nano slit pore, we calculated the solvation force and excess adsorption for hard sphere fluid confined in nano slit pore. solvation force and excess adsorption have oscillatory behavior.