AIMS: To examine perceived infection risk of COVID-19 and the health and related behavior changes among people with diabetes, compared with people without diabetes, and to examine factors associated with self-reported health during the national quarantine period in China. METHODS: The 2020 China COVID-19 Survey is an anonymous 74-item survey administered via social media across China. A national sample of 10,545 adults in all 31 provinces in mainland China provided data on sociodemographic characteristics, awareness, attitudes towards COVID-19, lifestyle factors, and health outcomes during the quarantine. Regression models tested associations among study variables adjusting for covariates. RESULTS: Among the 9,016 total participants (42.6% men and 57.4% women), 585 reported having diagnosed diabetes and 8,431 had no diabetes. Participants with diabetes perceived themselves to be at higher risk and were more worried about being infected with COVID-19 when compared to non-diabetic individuals (p < 0.001). During the COVID-19 pandemic, participants with diabetes were more likely to experience food and drug shortages and to increase their physical activity, compared to their counterparts. Among diabetic respondents, a high proportion of current smokers (74.1%) and drinkers (68.5%) reported increased amounts of smoking and drinking. People with diabetes were 11% less likely to report excellent or very good health. Having 150 min/week physical activity was positively associated with excellent or very good health (prevalence ratio, PR = 1.14, 95%CI 1.11-1.16). CONCLUSIONS: A high proportion of people with diabetes perceived risk of COVID-19 infection and increased their smoking and drinking during the pandemic.