The　long-term　evolution　of　space　debris　environment　has　been　analyzed,　taking　into　account　a　detail　traffic　model,　explosions,　collisions　and　the　effects　of　air　drag.　Space　debris　environment　analyzing　software　SDEAP　has　been　developed　based　on　evolutionary　model.　The　modeling　process　and　the　flowchart　of　SDEAP　are　also　depicted　in　this　paper.　BAU　and　NEX　have　been　contrastively　simulated　in　a　100　years　span,　the　primary　results　show　that　spacecraft　and　rocket　bodies　passivation　to　avoid　in-orbit　explosions　is　a　most　efficiency　measure　to　restrain　the　debris　rapid　growth.　Of　course,　there　are　uncertainties　in　space　debris　environment　modeling,　so　mathematical　statistics　is　to　be　used　to　diminish　the　uncertainties　in　the　subsequent　working.