In order to reveal the differences in the absorption and accumulation characteristics of metal elements in Azolla Lam., we determined and analyzed the contents of 12 metal elements in 21 strains from 8 species of Azolla. by ICP-MS. The differences and enrichment characteristics of metal elements in different species of Azolla. were compared. The characteristic metals of Azolla. were determined by principal component analysis, and the tested resources were classified by clustering method. The results showed that: (1) the variation coefficient of metal element contents in 8 species of Azolla was greater than 30%. The difference of Mo content between strains was the largest (127.73%), and the difference of Ca content between strains was the smallest (18.94%). (2) The enrichment ability of different kinds of Azolla to different metal elements in soil was different, and the enrichment coefficient was Mn > Mg > Mo > K > Cd > Ca > 1. (3) There were significant differences in the enrichment ability of different Azolla to metal element K, Mg, Mn, Zn and Mo among different species (P < 0.05). (4) The characteristic metal elements of Azolla are Cd, Hg, Ca, Mn, Cu, Zn, K and Cr. (5) The clustering results based on the contents of characteristic metal elements showed that when the genetic distance was 15, the 21 Azolla resources could be divided into 3 groups, which was basically consistent with the traditional classification. Among them, the strains ‘3006’ and ‘MH3-1’ had strong enrichment ability for heavy metals Cd, Cr and Hg, and were clustered into one category. The study suggests that there are interspecific differences in the enrichment of metal elements in Azolla, and this difference could be used as a reference for the classification of Azolla varieties.