The study aimed to verify the degree of including the values of tolerance in the books of Islamic education in the cycle 2 of the basic education in the Sultanate of Oman, by answering the following two questions: 1. What are the values of tolerance that should be included in the Islamic education books in cycle 2 of the basic education in the Sultanate of Oman in all its grades? 2. To what extent are of the values of tolerance included in the content of Islamic education books in cycle 2 of the basic education for grades (5-10) in the Sultanate of Oman? To answer these two questions, the researcher used the descriptive analytical approach because it's suitable for the questions and objectives of his study his study. He also prepared a list of tolerance values, which consists of 32 values, these values are divided into four axes (groups): Eight Values of ideological tolerance, eight values of social tolerance, eight values of cultural tolerance and eight values of political tolerance, and after that, it was proved that the tool used in the research was sincere by presenting (showing) it to a group of 20 arbitrators in the fields of curricula, teaching methods and psychology. In addition, the consistency of the used tool was verified using the coefficient of agreement between the researcher and another analyst through the Cooper equation and the agreement rate reaches 89%. Among the most prominent results of the study are the following: 1. The social tolerance axis ranked first with a rate of 53.91%. Then, the doctrinal tolerance axis with a rate of 17.36%. After that, the cultural tolerance axis with a rate of 15.13%, followed by the political tolerance axis with a rate of 13.59%. 2. Grade 8 book is ranked first among the grades of the stage in its inclusion of the values of tolerance, as it obtains 309 repeats at 26.57%, while the lowest is included in grade10 book which gets 111 repeats with a rate of 9.54%. In the light of the findings of the study , the researcher recommended the necessity of including the values of tolerance in the Islamic education curricula by curriculum developers, and paying attention to the values of tolerance that are included to a lesser degree, putting in consideration the balance in the distribution of tolerance values in the content of the Islamic education books in cycle 2 of the basic education in the Sultanate of Oman.