In　this　paper,　we　study　the　chaotic　dynamics　of　an　optomechanical　systems　coupled　to　a　non-Markovian　environment.　The　master　equation　of　the　system　is　derived　beyond　the　Markovian　approximation　and　the　maximum　Lyapunov　exponent　is　employed　to　quantify　the　generation　of　chaos.　In　contrast　to　the　majority　of　existing　studies　on　chaos　generation　in　optomechanical　systems,　our　work　highlights　that　the　influence　exerted　by　the　properties　of　the　environment　can　be　of　equivalent　significance　to　that　of　the　system　parameters,　and　in　certain　cases,　the　environmental　parameters　may　be　even　more　important.　The　numerical　results　show　that　the　memory　time　and　central　frequency　of　the　environment　play　crucial　roles　in　the　generation　of　chaos,　and　they　can　even　determine　whether　chaos　occurs.　In　addition,　we　also　investigate　the　influence　of　system　parameters　and　compare　them　with　the　environmental　parameters.　We　hope　the　results　presented　in　this　paper　open　a　new　direction　for　the　research　on　chaos　generation　and　attract　more　attentions　on　the　influence　of　the　properties　of　environments.