Under the resriction of physical geography, the distribution of potamogeton flora in Shaanxi is mainly in three regions, namely, Hanzhong, Guan zhong and Yulin areas. Most of the species distribute in a geographical regularity, showing some close relationships with the regional disposition of the water in various chemical features. The flow condition, type and depth of water, degree of water level fluctuation and base pattern of water seemed to be important habitat factors, which affect the occurence of many species in a varying extent. Species occurred in the varying habitats are mostly with a effective adaptability, but others with a certain selection to the habitats.