The researcher chose to study the political, economical, cuitural and social life of the Islamic Suitanate of Zanzibar during the reign of Sultan Barghash bin Said (11V.-144). Her study aims at identifying the power of Sultan Barghash in east Africa and his stand against the European colonial scramble towards the east of Africa. She also aims at discussing the importance of the strategic location of Zanzibar and the most important economical resources during his rule . Moreover, she examines his role in achieving the cultural prosperity of Zanzibar. Finally, she tackles the social classes of the Zanzibari society and its role in the religious, scholerly and social life in Zanzibar and the civilizing influences and interaction between Zanzibar and Oman. The study is divided into four chapters. The first one cencentrates on the political life in Zanzibar. The second chapter is devoted to the study of the economical life. The third chapter handles the cultural life in the era of Sultan Barghash. Finally, the forth and final chapter is mainly about the social life in Zanzibar. The study showed that Sultan Barghash had a wide powerful influence in east Africa. His authority included wide area extending from Somalia in the north to Mozambique in the south. Having fertile land, Zanzibari people grew anumber of crops in Zanzibar. Its strategic location also made it easy for the people to have commercial exchange with the other countries and to develop into an important commercial centre in the Indian Ocean. The Sultans tolerance and his encouragement of scholars also helped in getting many of them to emigrate to east Africa especially from Oman to Zanzibar. The study revealed a very important reality that is the varied types of people in the Zanzibari society came as a result of the natural emigration from different countries such as Oman Hadhramout, The Comoro Islands, Persia and India. By describing the most important customs and traditions spread in Zanzibar, the study showed similarity between these traditions and customs and those of Oman. This emphasizes the cultural and social communication between Oman and Zanzibar.