Abstract: OBJECTIVE  To observe the clinical efficacy and safety of Huangku Qingxin mixture in the treatment of premature ventricular beat (PVB) with yin deficiency and fire hyperactivity syndrome.METHODS   92 patients who met the diagnosis criteria of the PVB were enrolled and randomly divided into two groups. The control group was given metoprolol tartrate while the treatment group was additionally given Huangku Qingxin mixture. The course of the treatment was eight weeks. The changes of TCM syndrome score, QT interval, corrected Tpeak-to-Tend interval (TP-EC interval), heart rate variability (HRV) and the number of PVB before and after treatment were compared.RESULTS   The total effective rate of TCM syndromes in the treatment group was higher than that in the control group (P < 0.05). In terms of QT interval, TP-EC, HRV, and PVBs, both groups improved after treatment compared with before treatment (P < 0.01), and the treatment group was better than that of the control group (P < 0.05, 0.01). During the treatment, there was no adverse reaction in the treatment group, but one case in the control group.CONCLUSION  Huangku Qingxin mixture can improve the clinical symptoms of PVB patients with yin deficiency and fire hyperactivity syndrome, decrease TCM syndrome score and PVBs, shorten QT interval and TP-EC interval, improve HRV, and effectively treat PVB in yin deficiency and fire hyperactivity pattern with high safety.