Abstract: Parsimony Analysis of Endemicity (PAE) proposed by Rosen (1985) is analytical method for bigeography. The method, however, had some shortcomings, as it does not present a method to separate primitive and advanced taxa in their distribution areas. In the present paper, an improved PAE method is proosed to satisfy the demand. The primitive and advanced taxa are indicated by the signs 0 and 1 respectively. Both primitive and advanced characters of taxa are confirmed by means of taxon cladogram.

Key words: Biogeography