Objective:To evaluate the joint involvement in SLE through musculoskeletal ultrasound(MSUS)and analyze the relationship between ultrasound assessment and autoantibodies,inflammatory biomarkers and clinical scoring system.Methods: A total of 41 patients with SLE was included in February 2014 to February 2015 in Rheumatology Department,West China Hospital.We have recorded the general situation.We used MSUS to evaluate the hands,wrists and knees from four aspects(joint effusion,synovial hyperplasia,tenosynovitis,bone erosion)respectively and recorded evaluation scores.Results: In 41 SLE patients,with 26 painful joints(63.4%)and 39 ultrasound abnormal joints(95.1%),of which 13 wrist joints involved(31.7%); 7 MCP1 involved(17.1%),8 MCP2 involved(19.5%),17 MCP3 involved(41.5%),14 MCP4 involved(34.1%),5 MCP5 involved(12.2%); 2 PIP1 involved(4.8%),10 PIP2 involved(24.4%),17 PIP3 involved(41.5%),12 PIP4 involved(29.3%),3 PIP5 involved(7.3%); 12 knee joints involved(29.3%).In assessments of 984 joints,MCP is the most affected joint group,and the most serious joint group.Finally,we have found correlation between the MSUS score with dsDNA,RNP antibody(P < 0.05),and the MSUS score was significantly correlated with DAS28,serum level of IL-6(P < 0.01)in SLE patients.Conclusion: MSUS is a powerful tool to evaluate the affected joints and tendons than other imaging techniques.MSUS is highly sensitive to evaluate subclinical synovitis in SLE.The MSUS scores of patients are positively correlated with SLE autoantibodies,the level of interleukin 6 and DAS28 scores.