The Baoteng highway to be built in namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />Yunnan Province will be an international thoroughfare from Kunming to Myanmar and India and also an important component part of the Asian Highway Network. This paper made an analysis of the main landslide—No.1 landslide in the area of the Longjiang Giant Bridge in such aspects as its engineering geological conditions, morphological distribution, distribution mode, formation mechanism and resultant adverse factors and, on such a basis, put forward the idea that the joint structural plane constitutes the main factor controlling the formation and stability of the landslide of the Longjiang Giant Bridge, with underground water also having some adverse effects.