Compared with the standard cages, laboratory mice and rats prefer the cages enriched with nesting materials. Nesting materials provided in conventional mouse or rat cages can benefit the rodent''s wellbeing, and have been widely used in husbandry and management of laboratory mice and rats for improvement of welfare. Here, we review the background, application, and effect of nesting materials on environmental enrichment and welfare improvement for laboratory mice and rats. This review also provides a clue to improvement of laboratory animal welfare in our routine work. 