Abstract: Based on samp ling and measuring sap flow in taproo t of Caragana korsh inskii by Therma l D issipationProbe( TDP), data fo r 30 typ ica l sunny days w ere se lected for ana lyzing, it show ed that the transportat ion o f sapflow in taprootw as contro lled by atmosphere evaporat ion, canopy export and sapw ood area. Sapwood area played animportant ro le in ensuring w ater transport unblocked under high atmosphere evaporating and canopy transportingcond it ion. Itw as indica ted that the da ilymean sap flow velocity ofNo. 1 3 samp le treesw ere 457. 92, 1 014. 66 and292. 12 g?d-1 respect ive ly, and the sapw ood areaw ere 6. 61, 7. 17, and 5. 06 cm2 respectively, the form er variedaccording ly w ith the latter. Therew ere sign ificant d ifferences in sap flow velocity among the sample trees, wh ile nosign ificant d ifferences w ere found in sap flow velocity per leaf area, so leaf areawh ich characterized by canopy tran spiration dem andsmay be amore importan t variable than sapw ood area forw ater transport ing and so ilw ater fo r pro v id ing in soil p lant atmosphere con tinuum. The so ilmo isture cond it ion at depth from 60 to 140 cm in trial periodw as adapted for 3 sample trees o fCaragana korshinsk ii, wh ich accoun ted fo r 51. 04%, 63. 26% and 87. 0% of f ie ldmoisture capacity respectively. The daily variat ion pattern o f No. 2 w as related w ith Poten tial Evapotransp iration( ET0 ) more c lose ly than the o thers, so the ratio o f leaf area to sapwood area of No. 2 wh ich w as 0. 62m2? cm-2imp lied that the ab ility of sapwood transportationmatched w e llw ith canopy demands, and could be used as a b io log ical characteristic index for reflecting the hydro log ical adaptat ion ofCaragana korshinskii.