【Abstract】〓Objective〓To evaluate the ultrasonographic features of thyroid nodules related to inefficient operations of ultrasoundguided fineneedle aspiration (USFNAB). Methods〓 The ultrasonographic features and cytopathology results after USFNAB of 200 thyroid nodules from March 2011 to May 2012 were retrospectively analyzed. Based on the cytopathology results guided by Bethesda system, the operations of USFNAB with satisfactory and unsatisfactory samples were defined as efficient and inefficient respectively. The relationship between ultrasonographic features and inefficient operations were assessed. Results〓 The ultrasonographic features significantly related to inefficient operations were macrocalcification (P=0018), rich inner blood flow (P=0029), surrounding blood flow (P=0004), deep location(P=0038), peripheral vital structures(P＜0001),benign prediction by ultrasonography (P=004), subacute thyroiditis background(P=0029) and nodule size smaller than 10mm ( P=0013). Conclusion〓 It is important to recognize the ultrasonographic features related to inefficient operations to make intensive training and achieve efficient operation in USFNAB of thyroid nodules.