Abstract:Studied on the natural recovery plant community in abandoned lands in the Minqin Oasis,downstream of the Shiyang River,which developed in deferent years by the index of the important value,species richness Margalef index,Simpson and Shannon-wiener diversity index,Alatalo and Pielou evenness index.The result shows that:(1)Plants of 34 species spread over 14 families live through fifty years appeared in abandoned lands in the study area.Shrubs was 6 species and herbs was 28 species among them,which were 17.65% and 82.35% respectively.The goosefoot family(8 species),the grass family(6 species),caltrop family(4 species) were 52.94% among them.(2)The following process of the plant community succession experienced in fifty years in study area:Convolvulus arvensis→Chenopodium album→Sonchus oleraceus→Peganum nigellastrum→Peganum harmala→Halogeton glomeratus→Lycium ruthenicum→Reaumuria soongorica→Kalidium foliatum.(3)Fluctuated downtrend showed by species richness and diversity index with the succession time growth.Downtrend in the first stage (1～5a) then fluctuated uptrend in the second stage showed by evenness index.Above all,the number of the species gradually reduced along with the development of plant community succession towards positive direction in abandoned lands,which experienced four stages,that was,the rapid recovery stage (1～5a) of annual herbaceous and perennial root plants,annual herb successes to perennial herb stage (5～15a),perennial herbs successes to perennial shrub stage (15～30a),perennial shrub plant arrived a stable relatively stage (30～50a).