The purpose of this thesis is to study the concept of Papa in Theravada Buddhism. The content of the thesis is divided into two parts. Firstly, it is an examination of the concept of Papa in Theravada Buddhism, particularly, the meaning and its charateristics, as well as the classification and its negative consequences. Secondly, it is an analysis of the relation between Pana and life. The results of study can be summed up as follow : 1. Committing Papa is wrong by means of the three channels-body, speech and mind. 2. Papa affects human life both physically and mentally, Psychological impact can be seen from the stress in the mind of Papa-doer as well as in the present life or life after death.