The migration and dispersal of the oriental fruit fly, Bactrocera dorsalis Hendel, was studied using methyl eugenol-baited traps, in regions of Nujiang River, Yunnan, in July 2005, by mark-release-recapture method fluorescence powder as mark material. Recapture sites were set up at eastward, southward, westward and northward from release site, Lujiangba. After 7-day recapturing, 43 marked flies were recaptured at northern recapture sites from Lujiangba to Liuku along Nujiang River, and at the farthest site, 97 km from release site, 5 marked flies were recaptured. 17 marked flies were recaptured at southern recapture sites from release site, but the distances from release site were in 29 km. No any marked and no-marked flies were recaptured at western and eastern recapture sites. Analyses of topography and geographic landscapes of the region indicated that under suitable climatic conditions, the fruit flies of Lujiangba could achieve their longer movement and dispersal inside the Nujiang valley from south to north along Nujiang River in virtue of southern air current carry. Meanwhile further movement and dispersal of the flies to east and west was obstructed by the two higher mountain chains beside Nujiang River. Analyzing relationships of marked and no-marked flies in the northern recapture sites showed that both marked and no-marked flies had similar behavior patterns in spatial population dynamics. It was inferred that both marked and no-marked flies might come from the same original region. The study firstly reveals a special movement and dispersal phenomenon of B. dorsalis at the special valley region. The results provide fundamental data for establishing feasible and effective control strategy of the fruit fly in regions of Nujiang River.