This paper firstly aimed to examine modern the relevance between the speeches and behaviours of the characters in James Joyce`s Ulysses, the law of karma and the theory of reincarnation of Buddhism. The next goal was to show how the relevance deepened the philosophical meaning of Joyce`s Ulysses and how it played an important role in creating the artistic perfection in Joyce`s literary world. Lastly to clarify how the relevance makes a serio-comic effect which Joyce ultimately wanted to create in Ulysses. The law of karma and the theory of reincarnation are related to the idea that all life is continuous, that all beings are interconnected. This spirit of interconnectedness offers Stephen and Bloom a spiritual connection with Ultimate Reality. In Ulysses, the application of karma and reincarnation, because of the enormous breadth of their scope, is expressed in the theme of paternity. The father-son relationship between these two characters, a major and problematic theme, can be explained by recognizing the use of these two principles. Conclusively speaking, the pursuit and confirmation of paternity is a symbolic behavior which can be applied, not only to the connection between Stephen and Bloom, but also to all human beings existing in the same situation. It is also an important behavior of self-awareness which can be emancipated from the cycle of reincarnation and can reach the identity of Atman and Brahman.