Abstract: Alberto Ginastera is considered one of the most important composers in Argentina. His music reflects the ancient aboriginal primitivism and the nationalistic spirit of Argentine traditional music. Strong rhythm has played a significant role in his music. According to Ginastera¡¦s own criteria, his works can be divided into three periods, but only the first two periods are related to nationalistic music. The first period is called ¡§objective nationalism¡¨ (1937-1947), where folk elements are used directly in the works. The second period, called ¡§subjective nationalism¡¨ (1948-1953), is characterized by sublimated musical language. Ginastera uses new rhythmic and melodic materials that symbolize Argentine music. This thesis has four chapters besides the introduction. The time discussed in this thesis is until 1952, including Ginastera¡¦s early piano music up to his First Piano Sonata. All these compositions have the influence of the folk idiom of Argentina. The first chapter is a discussion of historical background, including the development and growth of art music in Argentine society and Ginastera¡¦s life as a composer. The second chapter focuses on the importance of the gaucho as a symbolic heritage of the indigenous folk music in Argentina and on how their music, such as malambo, gato, zamba, triste, vidala, and milonga were manifested in Ginastera¡¦s piano music. The third chapter studies Ginastera¡¦s compositional techniques and styles, including his treatment of form, phrasing, melody, harmony and tonality. This is followed by a comprehensive conclusion. Although Ginastera was not a prolific composer for the piano, his genius and creativity is shown by his outstanding skills in manipulating folkloric materials in his piano music. Ginastera¡¦s music has achieved widespread recognition and has also made a great contribution to the twentieth-century Latin-American music.