Objective:　This　study　was　performed　to　investigate　the　method　of　cranioplasty　in　patients　with　abnormal　bone　window　pressure　after　decompressive　craniectomy.　Methods:　We　performed　a　retrospective　analysis　for　25　cases　after　decompressive　craniectomy　in　patients　with　abnormal　flap　pressure　of　clinical　data.　Results:　Flap　pressure　increased　in　15　cases,　including　6　cases　of　hydrocephalus,　5　cases　of　contralateral　subdural　effusion,　2　cases　of　subdural　effusion　bone　window,　2　cases　of　bone　window　cystic　encephalomalacia　communicating　with　the　ventricle;　Flap　pressure　decreased　in　10　cases,　including　6　cases　of　hydrocephalus　after　ventriculoperitoneal　shunt,　and　4　cases　of　low　intracranial　pressure.　ALL　of　patients　were　treated　by　appropriate　measures　to　make　the　operation　smoothly.　Conclusion:　Our　data　suggest　that　after　analysis　of　the　factors　for　abnormal　bone　window　flap　pressure　by　decompressive　craniectomy　and　symptomatic　treatment,　the　difficulty　of　operation　and　operative　complications　can　be　reduced.　(C)　2016　Elsevier　B.V.　All　rights　reserved.