To evaluate the current status and similarities and differences in the legal frameworks for chronic disease prevention and control in Zhejiang and Shanghai, and to analyze their relationship with the effectiveness of chronic disease prevention and control, this study collected relevant laws and regulations in the chronic disease field from both regions. The level of protection provided by the legal systems was quantitatively assessed using four indicators: the completeness of laws and regulations, the degree of statutory status, the degree of rigid constraints, and the degree of proactive improvement of relevant laws. Spearman correlation and stepwise regression analyses were employed to examine the relationship between these indicators and the effectiveness of chronic disease prevention and control. The results indicate that the level of protection provided by the legal systems for chronic disease prevention and control in both regions shows an overall upward trend. There is a positive correlation between the level of protection and prevention and control outcomes, and the legal systems in both regions have a strong explanatory power (approximately 73%) regarding these outcomes, with Zhejiang slightly higher than Shanghai. Stepwise regression further reveals regional differences in influencing factors. The study concludes that both regions need to further strengthen the improvement and optimization of their chronic disease prevention and control legal systems based on their actual circumstances to better promote the in-depth development of chronic disease prevention and control work.