Abstract: Two species of fruit fly，Bactrocera dorsalis and B. correcta were marked，released and recaptured from Yuanjiang County to Kunming City in May，June and July in two years of 2004 and 2014. 2 000 fruit fly individuals were marked and released at Qinglongchang and 14 B. dorsalis and 42 B. correcta were recaptured in Mengyangba，which showed that two species of fruit fly could fly toward North along the corridor. 5 000 fruit fly individuals were marked and released at Yuanjiangba，70 B. dorsalis and 20 B. correcta were recaptured in Qinglongchangyakou，which indicated that two species of fruit fly could spread from Yuanjiangba to Qinglongchangyakou. 10 000 and 20 000 fruit fly individuals were marked，released and recaptured at Qinglongchangyakou in June and July respectively. The results showed that the flight distance of B. dorsalis attained to 150 km. B. dorsalis from Yuanjiangba could spread toward Kunming by means of Southwest air current and corridor formed by canyon or highway.