This study attempts to investigate the changes, both in content and form, of one hundred and one Thai short stories from 1964-1973. According to the study, these Thai short stories express the estrangement from modernization as well as hostility towards social establishments and values, and dictatorship. The themes of alienation, bleakness, and despair, all of which are reactions to urbanization, are common. Metaphors of confinement are used to express the dehumanization of urban life. The works question identity are meaning of life. The changes in form express the crisis of representation. The conventions of realism are rejected because they cannot represent the changing modern world. The disruption of the unity and the causality of plot structure is apparent. The works explore the inner self through various techniques. There is also an increase in the use of experimental modes of expression as influenced by the visual arts. Most works in this period show an interest in sophistication and mannerism. This transformation of Thai short stories reveals the influence of modernist literary works from the West. However Thai short stories in this period have a distinct characteristic in that they can be interpreted as a political act which is a reaction against autocratic administration. There are two phases of reactions. The first phase which appeared around 1964-1969 is a change of narrative form into a subjective mode indicating a flight from political reality into the consciousness. The second phase which occurred between 1970-1973 shows the use of experimental techniques of fragmentation, commonly found in plot structures and perspectives of modernist literature, art and films. The radical changes in content and style in modernist Thai short stories symbolize political and social crises in Thai society.