Objective: Evaluate the clinical application value of Tei index of Tissue Doppler Imaging (TDI) on the early left ventricular function changes of patients with prehypertension. Methods: Screening patients from January 2015 to August 2016 in Shigatse People’s hospital as research objects. Investigating case history, and having physical examination and blood biochemical examination. The patients were divided into three groups of normotension (NT),prehypertension(Pre-HT)and hypertension(HT). Each group will compare the changes in the indicators. Results: By comparison, the Tei index difference is significant (P<0.05) in each group. The Tei index difference of patients with prehypertension is significantly higher (P<0.05) than that of patients with normal blood pressure, while significantly lower (P<0.05) than that of patients with high blood pressure. After comparing patients with prehypertension and with normal blood pressure, the increase of index of ventricular wall thickness and quality is significant (P<0.05). Conclusions: Tei index is able to detect the heart function change at an early stage, and is crucial to early monitoring and prevention of high blood pressure and clinical ventricular function damage, as well as positive reversal of heart function.