80mmHg in all patients at stimulating test. Selected septal branch angiography was taken. The methods of target septal branch selection included balloon occlusion test, angiography through the catheter lumen, and ultrasonic echocardiogram monitor. The 1st septal branch was ablated in 6 patients, and in 2nd branch in 2. The volume of alcohol injected was 1 75~7 0ml. The results showed that the successful rate of PTSMA operation was 100%, and the clinical symptoms for all patients improved significantly with mean LVOTPG decreased by 68 3%?13 0% at the end of the procedure. No severe ventricular arrhythmia occurred. One patient was followed-up clinically and angiographically half a year after the operation and his LVOTPG was 0 mmHg and the NYHA heart function was raised to Ⅱ grade from Ⅳ grades before operation. PTSMA is a promising interventional technique for HOCM therapy with satisfactory short-term clinical outcome.