Objective The DNA methylation microhaplotype ( DMH) refers to the combination of multiple methylation sites within a very short range, and these haplotypes show wide diversity. We carried out screening and validation of age-related DMHs in mouse blood. Methods We initially constructed a theoretical dataset of DMHs based on the mouse reference genome. We then screened age-related DMHs by Spearman’ s rank correlation analysis, using highthroughput sequencing information for DNA methylation in mouse blood from a network database. Finally, cross-validation was performed using a validation dataset. Results A total of 6787 142 DMH sites were identified within 50 bp in the mouse genome, including 98. 64% of single-digit CpG sites. A total of 5835 age-associated DMHs were screened in 58 mouse blood samples ( |rho | > 0. 5, P<0. 01), accounting for 0. 086% of DMHs. Finally, we validated the top 100 ageassociated DMHs with high correlation in 95 independent samples, Results ing in 44 loci. Conclusions The age-associated DMHs screened in this study may be useful in future studies of apparent age prediction using mouse blood and in aging studies.