Objective To observe the relationship between plane QRS-T angle and NYHA cardiac function and prognosis in elderly patients with heart failure with preserved ejection fraction（HFp EF）. Methods A total of 204 elderly patients with HFp EF was divided into three groups according to the NYHA cardiac function classification standard（64 with NYHA class Ⅱ

85 with NYHA class Ⅲ

55 with NYHA class Ⅳ） and 74 with normal cardiac function were enrolled in control group. Plane QRS-T angle was detected with routine electrocardiogram on admission for every subject. Results The QRS-T angle（87.48°±23.25°）

BNP（348.4±169.03 pg/ml） and the incidence of poor prognosis（36.8%） in HFp EF group was significantly larger than those in control group（38.95°±16.89°

58.35±17.52 pg/ml

8.1%

p<0.05）. The QRS-T angle and the level of BNP increased gradually with the increase of cardiac function grade（p<0.05）. The QRS-T angle and BNP in poor prognosis group was larger than those in good prognosis group（p<0.05）. Conclusions QRS-T angle of elderly HFp EF patients has a close relationship with NYHA cardiac function and prognosis. Plane QRS-T angle can be used to assist in the diagnosis of HFp EF and the determination of the severity and prognosis of heart failure.