Abstract: In accordance with the characteristic of long distance buried pipeline system, structure model of pipeline system and failure probability model of pipeline under seismic wave are established in this paper. Based on probability theory, system theory and reliability principle, system reliability of pipeline is respectively analyzed to failure independence and dependence. Result shows that when site classification and earthquake intensity of every pipeline unit is identical, considering failure dependence is very essential to system reliability analysis of long distance buried pipeline under seismic wave.