Key L aborat ory of A dapt ati on and Evol ution of Pl ateau B iot a , Chi nese A cademy of S ciences , Xi ni ng , Qi nghai 810001 , Chi na) Abstract :(Objective)The paper st udied t he qualit y and shape of t he dia spo res of 43 plant species in2 volvi ng 13 seeds and 30 f r uit s f ro m alpi ne meadow i n t he so urce regio n of t hree river s.Met ho d)The dia2 spo res of 43 species were quantified ,shapes of t hem were scaled wit h variance of t hree di mensio ns ,and t he relatio ns bet ween above i ndexes and ecolo gical charact eri stics of diaspo res were analyzed.(Result)The re2 sult s show t hat t he qualit y of a si ngle diaspo re of 15 species i s less t han 1 mg ,and it s shape i s clo se to sp he2 ricit y because of variance less t han 0. 09 ,and it might have per si st ent soil seed bank ,and i s able to adap t to di st ur bance. The dia spo res of perennial s are heavier ,flat t er and lo nger t han t ho se of annual s. The diaspo res of fo r b are heavier ,and t ho se of her bages are flat t er and lo nger . Seeds are clo ser to sp hericit y i n co mpari so n wit h f r uit s. The diaspo res of mo st of Co mpo sit ae and Grami neae and Sedges species are flat and elo ngat ed because t he variance i s mo re t han 0. 09. The appendages of dia spo res play an impo rt ant role i n di sper sal and est abli shment . The dia spo res of 75 % Co mpo sit ae species have papp uses , and might be di sper sed by wi nd