In this article, fantastic genre as a literary genre which nowadays has significantly become common in contemporary literature of Russia, will be studied. "My Father is an Antibiotic" is an outstanding example of this genre, which has been written on the basis of critical conditions and abnormal events of the present world and their influence on humans' life. Afterwards, through introduction of Sergei Vasilivich Lokiyanenko as one of the pioneer fantast writers in modern literature of Russia, we will  examine his works and his motivations for choosing this specific genre. Sergei Lokiyanenko is a writer with a marvelous skill at portraying life in past, present and future, with the help of imagination and science. He wrote "My Father is an Antibiotic" in 1992. In Lokiyanenko's view, it is hard for contemporary man to get accustomed to modern lifestyle, numerous numbers of newspapers, increase of contacts, and new methods of communications. He believes that unprepared for facing such an attack, man's spirit sometimes prefers to sacrifice real world and sink in a world made by his own mind. In this novel, the writer tries to show that children are the main victims of abnormalities and pugnacities of adults in the present world. Through analysis of "My Father is an Antibiotic", as a fantastic work of Russian contemporary literature, we have also tried to somehow pave the way for the Iranian readers to get familiar with contemporary literature of Russia, particularly fantastic genre.