Urban　water,　gas　and　thermal　pipeline　networks　are　vital　lifeline　systems.Due　to　the　correlation　of　those　parameters　such　as　structural　properties　of　different　pipelines,　site　conditions　and　seismic　loads,　the　seismic　failure　events　of　pipelines　in　the　network　are　correlated.In　this　work,　an　analytical　model　is　proposed　for　the　seismic　reliability　analysis　of　the　pipeline　network　considering　correlated　failure　of　different　pipelines,　and　the　transfer　of　correlation　coefficients　of　random　variables　from　the　reliability　of　individual　pipeline　to　the　reliability　of　the　pipeline　network　is　also　presented.The　analytical　model　of　seismic　reliability　of　pipeline　structure　with　correlated　random　variables　is　developed　using　FORM　based　on　Nataf　transformation　and　orthogonal　transformation.The　correlation　coefficients　of　pipeline　failure　events　are　obtained　by　the　reliability　theory　of　structural　system.Furthermore,　the　network　reliability　method　is　utilized　to　evaluate　the　connectivity　reliability　of　network　systems　considering　correlated　failures　of　pipelines.Moreover,　the　Monte　Carlo　simulation　method　for　the　pipeline　network　reliability　evaluation　considering　correlated　random　variables　is　also　presented.The　case　study　results　show　that　the　strong　correlation　among　the　random　variables　that　control　the　individual　pipeline　performance　function　has　great　influence　on　the　reliability　of　pipeline　network.Compared　with　the　traditional　assumption　that　the　events　of　individual　pipeline　failure　are　independent,　the　strong　correlation　of　pipeline　failure　events　can　reduce　the　reliability　of　the　parallel　pipeline　network　by　more　than　15%.For　the　parallel　pipeline　network,　the　higher　the　topology　redundancy　is,　the　greater　the　impact　of　correlated　failure　of　pipelines　on　system　reliability　shall　be.That　is,　the　impact　of　pipeline　failure　correlation　becomes　more　significant　on　the　seismic　reliability　of　the　parallel　pipeline　network　with　higher　topology　redundancy.　©　2019,　Editorial　Office　of　China　Civil　Engineering　Journal.　All　right　reserved.