Objective: To assess the acute and mid-term results of cardiac function improvements and left ventricular outflow tract gradient (LVOTG)changes in 30 patients displaying hypertrophic obstructive cardiomyopathy (HOCM) treated with percutaneous transluminal septal myocardial ablation (PTSMA). Methods: PTSMA was intended for 32 patients comprising of 13 women and 19men (average years being 54.1 ± 15.5) to be treated in accordance with the following inclusion criteria: The New York Heart As-sociation(NYHA) definition for cardiac functional class Ⅲ or Ⅳ , or class Ⅱ but for whom medical therapies were not tolerated or with syncope; intraventricular septal (IVS) and left ventricular posterior wall (LVPW) hypertrophy asymmetrically associated with ratio of IVS to LVPW≥1.3 and LVOTG≥50 mm Hg at rest or ≥100 mm Hg at provocation (Valsalva maneuver). The target vessels were determined by coronary arteriography that demonstrated more than one septal branch and probatory balloon occlusion produced greater than 50% decrease of LVOTG. Once the target vessel established, the alcohol was administrated into septal ventricular via over-the-wire balloon. LVOTG was assessed by means of echocardiography measurements immediately after procedure and 3 months. Simultaneously, cardiac function class was also evaluated. Results: Two patients were abandoned prior to intervention due to inappropriate septal target vessels and DDD Pacemakers were chosed. Immediately after the procedure, resting LVOTG was reduced from 73.8 ± 35.5 to 16.6 ± 7.8 mmHg, at provocation LVOTG from 149.3 ± 42.5 to 61.9 ± 43.0 mmHg(P ＜0.0001 each) by echocardiography measurements. After 3 months, the mean New York Heart Association class was reduced from 2.8 ± 0.6 to 1.1 ± 1.0(P ＜ 0.0001) and the LVOTG also remained decrease(28.5 ± 6.4 mmHg at rest and 75.3 ± 11.6 mmHg at provocation). Conclusion: PTSMA is a promising nonsurgical technique for relief of symptoms and reduction of LVOTG in hypertrophic obstructive cardiomyopathy.