Abstract: Based on collection and investig at ion of the data from Ruili,Baoshan twons and Yingjiang, Longchuan counties during 1982 to 1994,the structure of fleas communities on Rattus flavip ectus have been described in quantity for first time.The results showed that ther e w ere the different cha racters of seasonal variatio n in tendency figures of the carry flea rate of rats and the constituent ratio of two dominant species in the continual 36 months.Also,ther e were the differ ent characters of in terannual fluctuation tendency figur es of the carry flea rate of rats,total flea index,constituent ratio of tw o dominant species,Shannon index and evenness of each 12 months average in the continual 11 to 13 years.As a constituent of these characters,the authors named these communities for Ruili as Xennop sylla cheop is L entistivalius f er inus,for Longchuan as Xennop sylla cheop is Lep topsylla seg nis,fo r Yingjiang as X.cheop is L.segnis and for Bao shan as Lsegnis X.cheop is.Compining w ith epidemic intensity analysis of Yersinia p estis,it was considered that the former three communites with the do minant species of K.cheop is more fitted the conserve and spr ead of Yesinia pesitis;and last one community with the dominant species of L.seginis is shortter m for the sustenance of Y.p esitis.T herefor e,it is necessary in further study of succession law of the fleas co mmunit ies on R. f lav ip ev tus and their char acters to guiding the community of hamful flea evolved into the harmfuless community by the metho ds of the chemical co ntrol and surrouding manag ement,so that people can eradicate the threaten from the plague.

Key words: cultivation mode, summer-sowing peanut, functional leaf, photosynthetic characteristic, yield.