Objectives:　This　study　aims　to　explore　the　value　of　ultrasonic　semi-quantitative　scoring　in　the　diagnosis　of　seronegative　rheumatoid　arthritis　(RA).　Patients　and　methods:　Between　January　2018　and　October　2023,　a　total　of　411　patients　(241　males,　170　females;　mean　age:　50.9　+/-　17.5　years;　range,　18　to　87　years)　were　included.　Of　these　patients,　296　were　diagnosed　with　RA　(including　131　with　seronegative　RA　[SNRA]　and　165　with　seropositive　RA　[SPRA])　and　115　with　non-RA　disease.　Ultrasound　examination　was　performed　on　all　patients　with　suspected　RA,　focusing　on　evaluation　of　synovial　hypertrophy　(SH),　power　Doppler　(PD)　signals,　and　bone　erosion　(BE)　for　three　to　six　months.　The　ultrasonic　joint　semi-quantitative　score　was　evaluated　for　the　sensitivity　and　specificity　of　detecting　seronegative　RA.　Results:　The　three　indexes　of　SH,　PD,　and　BE　were　not　significantly　different　between　the　SNRA　and　SPRA　groups　(p=0.223,　p=0.176;　p=0.272,　respectively).　However,　there　were　differences　on　the　SH1,　SH3,　PD,　and　BE　grades　between　the　SNRA　group　and　the　non-RA　group　(p＜0.001　for　all);　when　serology　was　negative　and　when　the　highest　scored　joint　met　PD　Grade　＞=　2　or　BE　Grade　＞=　2,　it　showed　both　high　sensitivity　(93.12%)　and　high　specificity　(91.30%)　for　the　diagnosis　of　RA.　Conclusion:　Ultrasound　combined　with　semi-quantitative　scoring　is　of　promising　significance　in　the　early　diagnosis　of　SNRA　patients.