Abstract: The paper is an attempt to use the orders of Arachnida for checking the importance of the lines of Wallace, Lydekker and Weber for the distribution of these animals. From the orders of Arachnida some (Ricinulei and Solifugae almost) are missing from the analyzed area (Indomalayan and Australian regions). The distribution of the other orders relatively to the “lines” has been analysed. None of the orders of Acari (Opilioacarida, Prostigmata, Acaridida, Oribatida, Mesostigmata, Ixodida and Holothyrida) is limited by the “lines”. There is no order of Arachnida living only on one side of the “lines”. Only the spider suborder Mesothelae seems to be limited to the Western side. It is to notice the Vachon’s opinion (1953) (“On peut cependant affirmer que la ligne Wallace pour certaines formes de Scorpions — est une frontière réellement existante”) — it could be confirmed what concerns the scorpions. There are families and genera known only on one side, but it is a relatively low level of endemism. Nothing similar to the endemic orders and even subclasses in the vertebrates which are the base of the construction of the lines exists what concerns the Arachnida.