Hypertrophic cardiomyopathy is a cardiac disease with highest incidence rate in cats. It has no obvious symptoms in the early stage and is easily ignored by the owner. Once symptoms appeared，it often has poor prognosis. This paper reports a case of hypertrophic cardiomyopathy in a mix breed cat. With the medical history and results of clinical examination，hematological examination，X ? ray and cardiac ultrasound，hypertrophic cardiomyopathy was diagnosed. After 1 week of comprehensive treatment，which includes oxygen therapy，cardiac load reduction， thrombosis prevention and nutritional support treatment，the cat’s condition was stabilized.