Abstract: Objective To investigate the impact of different blood pressure control statuses on newly developed left bundle branch block（LBBB）. Methods Aretrospective cohort study was conducted. A total of 88 553 Kailuan employees who underwent health examinations from July 2006 to October 2007 were recruited and categorized into non-hypertension and hypertension groups based on the blood pressure values and hypertension history at the beginning of follow-up. The hypertensive patients were further divided into two groups: initial blood pressure controlled group and initial blood pressure uncontrolled group based on the blood pressure values at the beginning of follow-up. According to the blood pressure value at the end of follow-up, the patients with initial blood pressure uncontrolled were divided into the follow-up blood pressure controlled group and uncontrolled group. The impact of different blood pressure control statuses on the occurrence of newly developed LBBB was analyzed using a multifactorial Cox proportional hazards model. Stratified analyses by age and gender were performed, along with sensitivity analyses excluding participants with diabetes, chronic kidney disease（CKD）, heart attack, or heart failure. Results The non-hypertension group comprised 50 505 individuals, while the hypertension group comprised 38 048 individuals. Among the hypertensives, 2 607 patients had controlled blood pressure and 35 441 patients had uncontrolled blood pressure at the beginning of follow-up. Among the patients with uncontrolled initial blood pressure, 10 658 patients had controlled blood pressure and 24 783 patients had uncontrolled blood pressure at the end of follow-up. Over a follow-up period of（10.15±3.44） years, a total of 1 010 cases of LBBB occurred. The incidence density of LBBB was 0.80/1 000 person-years in the non-hypertension group, 1.58/1 000 person-years in the hypertension group（Log-Rank test P＜0.001）, 1.04/1 000 person-years in the initial blood pressure controlled group, 1.62/1 000 person-years in the initial blood pressure uncontrolled group, 1.32/1 000 person-years in the follow-up blood pressure controlled group, and 1.76/1 000 person-years in the follow-up blood pressure uncontrolled group. The results of the multifactorial Cox proportional hazards model analysis showed that adjusting for various influencing factors, compared with the non-hypertension group, the hazard ratio（HR） of developed LBBB was 1.42（95%CI: 1.24-1.62） in the hypertension group, and which was 0.97（0.66-1.44） and 1.45（1.27-1.66） in the initial blood pressure controlled and uncontrolled group, 1.27（1.04-1.54） and 1.53（1.33-1.77） in the follow-up blood pressure controlled and uncontrolled group, respectively. Conclusion Hypertension serves as a risk factor for newly developed LBBB, and achieving blood pressure control standards can reduce the risk of new-onset LBBB.