Between the years of 1845 to 1849, prevalence of a pathogenic fungi plant diseases resulted to the destruction of a large part of the potato crops of Ireland. This great disaster caused many changes in the political, social and cultural situation of Ireland and Britain. The fanatically religious beliefs of Irish and theirs adherence to superstitions and the subtle policy of the United States of America administration in attracting Irish immigrants, along with the changes occurred in Irish literature are some considerable issues of this event. In this paper, the authors tried to show the interaction of involved factors between and after the events and to present the tangled political, religious and cultural factors in this country. The emergence of the science of plant disease or plant pathology (phytopathology) as a result of efforts of scientists during several centuries that has recognized as a outcome of the that famine, the shake of some weak basis of sciences and the importance of the attention of scholars of humanities, in the social, historical and economics fields, to some areas such as the role of the organisms which causing damage to crops in the formation of economic, social, cultural and political changes, have been noted in this paper.