Objective To investigate the contamination levels of 11 mycotoxins such as aflatoxins in cereals and cereal products in Chongqing City， and to analyze the co- occurrence patterns of these mycotoxins， so as to provide basic data for the safety risk assessment， monitoring， and management of mycotoxins.Methods Using the monitoring data of mycotoxins levels in 358 cereal and cereal product samples in Chongqing City between 2016 and 2020， correlation cluster analysis and principal component analysis were adopted to analyze the correlations of the occurrence of multiple mycotoxins in different cereal and cereal product samples and the main contamination patterns.Results The contamination levels of the 11 mycotoxins were generally low across all samples. However， simultaneous contamination with multiple mycotoxins was observed in a high proportion of individual samples （5.31%-92.00%）. Corn and corn grits demonstrated significantly higher contamination levels of mycotoxins than paddy and rice， with 16.00% and 8.99% co-contaminated with six or more mycotoxins， respectively. Mycotoxins within the same class showed high inter-correlations and comparable contamination levels. Detection rate comparisons and principal component analysis indicated that Fusarium metabolites constitute the predominant contaminant category in cereals and cereal products.Conclusion Mixed mycotoxin contamination is prevalent in cereals and cereal products in Chongqing City， particularly in corn and corn products. Continuous monitoring is recommended， along with intensified field-based fungal prevention and control， and improved storage management during distribution， to reduce mycotoxin contamination levels in cereals and cereal products.