BACKGROUND　AND　OBJECTIVES:　The　correct　positioning　of　the　transverse-sigmoid　sinus　junction　(TSSJ)　during　retrosigmoid　craniotomy　(RC)　is　crucial　for　enhancing　surgical　efficiency　and　preventing　complications.　An　augmented　reality　technology　may　provide　low-cost　guidance　for　the　TSSJ　position.　The　authors　aimed　to　investigate　the　clinical　application　of　a　self-developed　mobile　augmented　reality　navigation　system　(MARNS)　for　TSSJ　positioning　during　RC　and　present　their　findings.　METHODS:　This　observational　research　enrolled　patients　who　underwent　RC　at　Fujian　Provincial　Hospital　from　May　2023　to　June　2023.　All　patients　had　their　TSSJs　located　by　MARNS.　The　surgical　incision　and　skull　＂keyhole＂　for　drilling　were　determined　separately　based　on　the　projections　of　TSSJ　on　the　3-dimensional　model　displayed　by　MARNS.　This　method　was　assessed　using　matching　error,　positioning　time,　integrity　of　the　bone　flap,　incidence　of　transversal　sigmoid　sinus　injury,　and　other　complications.　RESULTS:　Seven　patients　diagnosed　with　acoustic　neuroma,　trigeminal　neuralgia,　and　hemifacial　spasm　were　enrolled　in　this　study.　The　MARNS　system　exhibited　a　matching　error　with　an　average　magnitude　of　2.88　+/-　0.69　mm.　The　positioning　procedure　necessitated　an　average　duration　of　279.71　+/-　27.29　seconds.　In　every　instance,　the　inner　edge　of　the　TSSJ　was　precisely　identified　and　exposed　while　the　bone　flap　was　successfully　formed　and　maintained　an　average　integrity　of　86.7%.　CONCLUSION:　This　study　demonstrated　the　efficacy　of　MARNS　in　the　precise　placement　of　the　TSSJ　during　RC　procedures.　It　offers　advantages　for　convenience,　cost-effectiveness,　and　reliability　for　neurosurgical　navigation.