Objective: We investigated status of hypertension in a large opportunistic screening study in China from 2017 to 2023. Design and method: Data was derived from May Measurement Month (MMM). MMM China project strictly followed the international MMM protocol. Study participants had to be >= 18 years of age and had ideally not taken blood pressure for >= 1 year. Blood pressure was measured three times consecutively in the sitting position with a 1-minute interval, using a validated electronic BP monitor or mercury sphygmomanometer. Trained volunteer investigators administered a questionnaire to collect information on medical history, lifestyle, and use of medications. Results: Since 2017, more than 1600 measurement sites have been set up, and 1.7 million adult blood pressure measurements have been completed. Mean systolic blood pressure and diastolic blood pressure over the years is around 119-124mmHg, and 74-81 mmHg, respectively. From the results of MMM program, about 30% (24.7% to 29.2%) had hypertension. Through 3 years of efforts, the awareness (46.9% in 2017 to 51.5% in 2019), treatment (40.7% in 2017 to 48.4% in 2019), and control (15.3% in 2017 to 29.1% in 2019) rates of hypertension in China have improved. However, after COVID-19, the awareness (45.3% in 2020 to 16.0% in 2023), treatment (39.7% in 2020 to 14.3% in 2023) and control (24.2% in 2020 to 7.1% in 2023) rate of hypertension have declined. The main barriers to blood pressure awareness in China included age, gender, and body mass. The awareness of hypertension was higher in patients with comorbid diseases, such as diabetes mellitus, coronary heart disease, stroke or TIA, or the use of statins, than those without. The main barriers affecting hypertension control in China included age, gender, smoking and low proportion of combination therapy. Conclusions: The situation of low control rate of hypertension needs to be changed as soon as possible. Several modifiable factors as barriers to blood pressure control in China, such as current smoking, and the under-use of combination therapy warrants attention.