The diagnosis of fatty liver (steatosis) is made when fat in the liver exceeds 5-10% by weight. Fatty liver (FL) is commonly associated with alcohol or metabolic syndrome (diabetes, hypertension, obesity, and dyslipidemia), but can also be due to any one of many causes. Most people were detected from serum lipid abnormalities in the physical examination, and confirmed as the fatty liver disease by ultrasound imaging. In some previous studies, ultrasound was reported to provide an accurate and reliable measurement tool for the thickness measurements of subcutaneous adipose tissue. This method can overcome some limitations of the skinfold thickness measurements. Ultrasound (US) B mode image is an alternative method to measure tissue structure and has proven to be an accurate technique to measure subcutaneous fat thickness. However, pressing the transducer onto the skin with too much force will significantly reduce the subcutaneous adipose tissue thickness. In this study, a force controlled system combined with US transducer was used for 3D subcutaneous fat imaging and reconstruction. Finally, the correlations between body fat percentage and subcutaneous fat in steatosis patients have been investigated. The body fat percentage was determined by dual energy X-ray absorptiometry (DEXA, GE Lunar iDXA canner) and bioelectrical impedance analysis (BIA, Omron，HBF-370), and then, the correlation between body fat percentage and subcutaneous adipose tissue in normal and steatosis patients have been evaluated.