The ecological habit of Sergentomyia koloshanensis was investigated in Wenxian of Gansu Province and Nanping of Sichuan Province. This sandfly could be found from the last ten-day period of May to the first ten-day period of October, with a peak in the middle ten-day period of August. Its adult season covered as long as 4 and half months. It was exophilic with a vertical distribution reaching as high as 1640 m. At daytime, it rested in the caves and at the basal parts of boulder along the riverside, and it was difficult to find it in the residential areas; at night it moved about near the resting places, without human blood preference. By analyzing the available data of the description of sandfly species, it was found that Sergentomyia koloshanensis distributed mainly in the subtropical zone in China, with much less distribution in warm-temperate and marginal tropical areas.