It tells in a popular form about the biology of dog breeding and those problems of amateur dog breeding that have not yet been covered in domestic literature, but need it, since the success of breeding depends not least on them. The basis was the lectures for students of cynological courses given by the author in 1991–1992. at St. Petersburg State University and organized by the service dog breeding club DOSAAF together with the Department of Vertebrate Zoology of St. Petersburg State University. The wishes of the cadets largely helped determine the range of issues discussed. For breeders, amateur dog breeders, owners of private kennels and a wide range of readers.