An English Bulldog 4 years old, Queen was hospitalized three weeks after mating as anorexia, decreased activity, hamorrhagic pus like vaginal discharge, and high fever. It was very difficult to diagnose by clinical signs and clinical pathological findings, at the first. Eenlarged uterus cavity, fluid accumulation in uterus was clearly identified by radiography and ultrasonography. The results suggest that X-ray and ultrasound is very important diagnostic method for pyometra to know disease progress.