A Na-X type zeolite is one of the effective material to collect and/or decompose chrolofluorocarbons, CFCs. The CFC-11 molecular adsorption and/or decomposition behavior in a Na-X type zeolite framework under the condition of various number of containing molecules and of two kinds of different temperatures were calculated by a molecular dynamics (MD) simulation. As the results of calculation, the crystal structure of Na-X zeolite absorbing few CFC-11 molecules was stable at both 300 and 1000K. Putting more CFC-11 molecules into Na-X zeolite pores, water and CFC-11 molecules less stabilized at 300K and CFC-11 molecules decompose easily at 1000K. The framework of Na-X zeolite including 80 molecules of CFC-11 destructed instantly even at 300K. When 80 CFC-11 molecules were in Na-X zeolite unit cell, the framework was decomposed. From the experimental result at 673K, hydrochrolic and hydrofluoric acid produced by decomposition of CFC-11 have attacked and alumina bonds in Na-X zeolite framework and less stabilized. The MD simulation is consistent with these experimental results which we have reported previously.