The thesis deals with philosophical aspect of Dzhgchen, which is the core of the Yungdrung Bon traditon. It is very special spiritual tradition because of it's very special nondualistic view of man and universe. First part deals with the history and division of it's teachings and it's Dzogchen lineages. Next part focuses on explanation of differences in views of sutra, tantra and Dzogchen, mainly from the standpoint of the view of base, path, fruit, emptiness, clarity, conscioussness and mind and it's nature. Next part provides translation of the text Twelve little tantras and it's deep explanation. Last part, and most important one, focuses on philosophical examination of some key aspects of Dzogchen, mainly on it's view of autenticity of mindnature. This part also compares Pramenides's fragments with some key points of view of Buddhism and Dzogchen, which may lead to some unexpected conclusions about man's thinking and the problem of it's intentionality.