Background: The proportion of the population with allergic diseases has increased rapidly in recent decades. Studies on the prevalence of allergens contribute to the treatment and prevention of allergic diseases. Although many studies have been published on the prevalence of allergens in China, there are limited studies on the geographic distribution of allergens. Objective: The aim of this study was to explore the prevalence patterns of sensitization to allergens among patients with allergic diseases in all the seven geographic regions of mainland China. Methods: A large epidemiological study was conducted on the prevalence patterns of serum allergen-specific IgE (sIgE) sensitization to the four most common food allergens and five aeroallergens among 44156 patients with allergic symptoms from 2015 to 2018. The data were analyzed using the chi-square test, and descriptive statistics, forest plots and geographic heatmaps. Results: First, house dust mites were the allergen with the highest prevalence of sensitization in all seven regions, with the highest in South China (40.79%) and the lowest prevalence in Northeast China (11.21%). The prevalence of allergens varied in different regions and seasons. Second, the prevalence of sensitization was significantly higher among male than female subjects. Third, except for egg whites and milk, which had the highest positive rates in children, sensitization to other allergens tended to be the highest in teenagers and young adults. Conclusions: Our findings could help clinical staff apply effective treatment to unique patient groups and direct researchers to conduct deeper studies on the epidemiology of allergic diseases.