BACKGROUND　Supra-　and　infratentorial　acute　epidural　hematoma　(SIEDH)　is　a　common　posterior　cranial　fossa　epidural　hematoma　located　at　the　inner　surface　of　the　squamous　part　of　the　occipital　bone　(SOB).　Traditionally,　surgical　treatment　of　the　SIEDH　requires　a　combined　supra-infratentorial　craniotomy.　AIM　To　analyze　the　morphological　characteristics　of　the　SOB　and　introduce　a　single　supratentorial　craniotomy　for　SIEDH.　METHODS　Skull　computed　tomography　(CT)　scan　data　from　32　adult　patients　were　collected　from　January　1,　2019　to　January　31,　2020.　On　the　median　sagittal　plane　of　the　CT　scan,　the　angle　of　the　SOB　(ASOB)　was　defined　by　two　lines:　Line　A　was　defined　from　the　lambdoid　suture　(LambS)　to　the　external　occipital　protuberance　(EOP),　while　line　B　was　defined　from　the　EOP　to　the　posterior　edge　of　the　foramen　magnum　(poFM).　The　operative　angle　for　the　SIEDH　(OAS)　from　the　supra-　to　infratentorial　epidural　space　was　determined　by　two　lines:　The　first　line　passes　from　the　midpoint　between　the　EOP　and　the　LambS　to　the　poFM,　while　the　second　line　passes　from　the　EOP　to　the　poFM.　The　ASOB　and　OAS　were　measured　and　analyzed.　RESULTS　Based　on　the　anatomical　study,　a　single　supratentorial　craniotomy　was　performed　in　8　patients　with　SIEDH.　The　procedure　and　the　results　of　the　modified　surgical　method　were　demonstrated　in　detail.　For　males,　the　ASOB　was　118.4　4.7　and　the　OAS　was　15.1　+/-　1.8;　for　females,　the　ASOB　was　130.4　+/-　5.1　and　the　OAS　was　12.8　+/-　2.0.　There　were　significant　differences　between　males　and　females　both　in　ASOB　and　OAS.　The　smaller　the　ASOB　was,　the　larger　the　OAS　was.　The　bone　flaps　in　8　patients　were　designed　above　the　transverse　sinus　intraoperatively,　and　the　SIEDH　was　completely　removed　without　suboccipital　craniotomy.　The　SOB　does　not　present　as　a　single　straight　plane　but　bends　at　an　angle　around　the　EOP　and　the　superior　nuchal　lines.　The　OAS　was　negatively　correlated　with　the　ASOB.　CONCLUSION　The　single　supratentorial　craniotomy　for　SIEDH　is　reliable　and　effective.