Microcanonical molecular dynamics(MD) simulations for simple fluids with shifted Lennard-Jones potential have been carried out. The fluids system is confined between two solid surfaces with a distance of few molecular diameter. Therefore, the system is periodic in x and y directions and confined by an external wall along z direction. Various results are obtained depending on equilibrium property appeared in different conditions, e.g, size of the cell, number of particles and temperature, etc. Specially, we focused on the systematic change of the phenomena with varing temperature, density of the system and potential energy strength. We observe the adsorption phenomenon by density profile. Next we developed a molecular dynamics method to evaluate the full Lyapunov spectrum for fluids confined between walls. From these data, we observed the instability of the dynamics associated with adsorption process and the phase transition. Lyapunov exponents essentially provides a connection between the thermodynamics and dynamical behavior of confined system. The simulation presented here will be extend to the system with tight pores to study the fluid structure and its transport.