Ultrasonography observations were made of the kidneys of 21 dogs. Ultrasonography images obtained in transverse and longitudinal planes. A 3.5-MHz linear transducer was used. All examinations were peformed on dogs in dorsal recumbency under anesthesia. The right kidney was 3.2~3.8cm long, 1.7~3.5 cm wide and 1.0～1.9cm deep in 0～5 of body weight group, 3.6~4.6cm long, 2.4～3.6cm wide and 1.4～2.1cm deep in 5～10 of body weight group, and 4.6～6.4cm long, 3.3～4.2cm wide and 2.0~2.0cm deep in 10～15kg of body weight group(p< 0.01). Diameter of the parenchyma of the right kidney ranged between 0.4～0.9cm in 0～5kg group, 0.6～1.0cm in 5～l0kg group and 0.9-1.1cm in 10~15kg group(p<0.01). Diameter of the renal sinus of the right kidney ranged between 0.3～0.5cm in 0～5kg group, 0.4～0.7cm in 5～10kg group and 0.5～0.9cm in 10~ 15kg group(p< 0.01). Similar ultrasonic measurements were obtained for the left kidney. It was concluded that the ultrasonographic findings described in this study can be used as references for diagnosis of morphologic changes in e canine kidney.