INTRODUCTION: China faces the dual challenge of high air pollution and an increasing burden of cardiovascular disease (CVD). We aimed to estimate the healthcare costs associated with CVD and the quality-adjusted life years (QALYs) under scenarios of improved air quality in China. METHODS: A health prediction model was developed to estimate 10-year CVD-related costs and QALY associated with PM2.5 levels in 2015, as well as two hypothetical improved air quality scenarios: (1) the China national PM2.5 target of 35 µg/m³, and (2) the World Health Organization's (WHO) PM2.5 guideline of 5 µg/m³. Population CVD risks were estimated from the 2015 China Health and Retirement Longitudinal Study. Hazard ratios from WHO risk curves were subsequently applied to baseline cardiovascular risks to predict national 10-year estimates of ischaemic stroke and coronary heart disease-related healthcare expenditures and QALYs for individuals aged 45-85 under the three air quality scenarios. RESULTS: Under PM2.5 levels in 2015, we estimated a cumulative 10-year incidence of 35.40 million CVD events, resulting in healthcare costs of US$96.12 billion and 4.44 billion QALYs. Under the national target of 35 µg/m³, the projected 10-year CVD incidence was 31.92 million cases, resulting in cost savings of US$9.29 billion and 3.43 million QALY gains compared with 2015 levels. If PM2.5 concentration levels meet the WHO's guideline of 5 µg/m³, the projected number of CVD events would decrease to 24.18 million, translating to cost savings of approximately US$30.10 billion and gains of 11.29 million QALYs. CONCLUSION: Our findings indicate that achieving the WHO recommended PM2.5 concentration level of 5 µg/m³ could lead to over threefold greater health and economic benefits than those achievable under national standards of 35 µg/m³. This underscores the potential need for stricter future national PM2.5 standards. Our findings also inform other low- and middle-income countries in establishing effective long-term PM2.5 targets.