Disclosed is a method for extending lifespan in a subject. By screening for mutations that enhance resistance to multiple stresses, the invention identified multiple alleles of alpha-1, 2-mannosidase I (mas1) which, in addition to promoting stress resistance, also extended longevity. Meanwhile, longevity enhancement of a subject is also observed when either the expression of mas1 or its downstream gene Edm1 is reduced. Furthermore, this invention also found that the down-regulating mas1 and Edm1 may extend longevity by modulating DR (Dietary Restriction). Thus, via molecular biology techniques, the expression of the target genes such as mas1 and Edm1 can be regulated, and the lifespan extension for a subject also can be achieved.