In　this　study,　the　window-modulated　compounding　(WMC)　technique　was　integrated　into　three-dimensional　(3D)　ultrasound　Nakagami　imaging　for　improving　the　spatial　visualization　of　backscatter　statistics.　A　3D　WMC　Nakagami　image　was　produced　by　summing　and　averaging　a　number　of　3D　Nakagami　images　(number　of　frames　denoted　as　N)　formed　using　sliding　cubes　with　varying　side　lengths　ranging　from　1　to　N　times　the　transducer　pulse.　To　evaluate　the　performance　of　the　proposed　3D　WMC　Nakagami　imaging　method,　agar　phantoms　with　scatterer　concentrations　ranging　from　2　to　64　scatterers/mm(3)　were　made,　and　six　stages　of　fatty　liver　(zero,　one,　two,　four,　six,　and　eight　weeks)　were　induced　in　rats　by　methionine-choline-deficient　diets　(three　rats　for　each　stage,　total　n　=　18).　A　mechanical　scanning　system　with　a　5-MHz　focused　single-element　transducer　was　used　for　ultrasound　radiofrequency　data　acquisition.　The　experimental　results　showed　that　3D　WMC　Nakagami　imaging　was　able　to　characterize　different　scatterer　concentrations.　Backscatter　statistics　were　visualized　with　various　numbers　of　frames;　N　=　5　reduced　the　estimation　error　of　3D　WMC　Nakagami　imaging　in　visualizing　the　backscatter　statistics.　Compared　with　conventional　3D　Nakagami　imaging,　3D　WMC　Nakagami　imaging　improved　the　image　smoothness　without　significant　image　resolution　degradation,　and　it　can　thus　be　used　for　describing　different　stages　of　fatty　liver　in　rats.