Polyporus umbellatus (Pers.) Fries is an endangered medicinal fungus in China with in vivo anticancer activity, but its genetic information is lacking. Eight natural P. umbellatus strains collected from 7 provinces in China were subjected to sequence-related amplified polymorphism markers to estimate the level and pattern of genetic diversity. Forty-nine primer combinations generated 1219 highly reproducible and discernible loci, among which 1023 were polymorphic. The percentage of polymorphism varied from 35.71 to 96.30 with an average of 83.92.