This research is of three objectives, namely : 1) to study the Eight Precepts in Theravãda Buddhist Scriptures, 2) to study the observation of the Eight Precepts by Phra Bodhisatvas (The Buddha Would-Be) as appearing in the Theravãda Buddhist Scriptures, 3) to analytically study the observation of the Eight Precepts by the Bodhisatvas (The Buddha Would-Be) as appearing in the Theravãda Buddhist Scriptures to be applied to the present Thai societies.

From the research, it is found that the Eight Precepts mean the ways of presently living with the way of not taking the food by observing the  Eight Precepts on the important days in Buddhism. Such days are called “Uposotha Days” which are the waxing and the waning moon of 8^th day and 15^th day in each month. The Uposothasîla consists of 8 organs. The Eight Precepts observed on the Buddhist days are called the Uposothasîla. The precepts which are observed on the other day are not called Uposothasîla.

The methods of observing the Uposothasîla by the Bodhisatvas is  the way of observing the precepts and the practical on the 14^th and 15^th day in each month for attaining the enlightenment. The Bodhisatvas took a little food to control his faculties before observing the  Eight Precepts and did not re-act to the one who harms Him.  This is the observation of the Eight Precepts at the level of Upapãramî and Paramatthapãramî for the highest aim, that is to attain Sabban๎n๎utan๎ãrana in the future.

Most of the male and the female disciples who observe the Eight Precepts in the present Thai societies are in lack of the knowledge and the understanding of the way of observing the Eight Precepts. They must depend on the monks in their observing the Eight Precepts.  Moreover, they must support the temples to set up the activities in observing the Eight Precepts which are the patterns of observing the Eight Precepts. By this way, they can protect Buddhism for ever.