This paper divides into five sections, except Instruction and Conclusion, the second section divides into four subsections: The first sub-section is the Content of the Buddhavaṃsa. The second is the Form of the Description: Although the way of the description of every Buddha is a little bit different, the same is the other twenty-four past Buddhas all prophesied to the former lives of Gotama Buddha that he would become a Buddha after incalculable kappas. Dīpaṅkara Buddha is the first Buddha to prophesy the previous lives of Gotama Buddha, from then unfold the practice of Gotama Buddha's previous lives in incalculable kappas. The third sub-section is the comparison of the twenty-five Buddhas: The Dhamma of all the Buddhas penetrated is the same, but the body and practice time of austerities, etc. are different. The fourth sub-section is the act of the previous lives of Gotama Buddha. The third section discusses the differences between the Buddhavaṃsa and the Buddhavaṃsaṭṭhakathā: Compare the verses of the both, some verses occur in the text do not give in the Commentary, and vice versa. This section tries to find out the possible reason to be so. The fourth section discusses the possible dating of the Buddhavaṃsa. The fifth section is Conclusion. The Buddhavaṃsa is a description of the attainment of Buddhahood of twenty-five Buddhas. In the text the Buddha Gotama spoke in the first person in which describes his various identity at that time of these twenty-four Buddhas. He talked about how he paid homage to the past Buddhas and resolved to attain Buddhahood and how these past Buddhas prophesied that he would become a Buddha after incalculable kappas. The text on one hand simply mentions the history of previous Buddhas, on the other hand mentions the identity of Gotama Buddha at that time while those Buddhas arose. The text belongs to the birth stories of Gotama Buddha. Great emphasis is placed on unbroken lineage in Indian culture also. In this way the idea of session of Buddhas implies that Gotama Buddha was not the first Buddha and after him there will be future Buddha such as Metteyya Buddha. The Buddhavaṃsa establishes an ideology of Buddha lineage, it becomes a norm for anyone on the path to Buddhahood.