This study seeks to unveil the art of letters in the Umayyad era and understand their methods and characteristics. Al-Hasan al-Basri was chosen as a model by studying his letters and clarifying their methods. The study concluded that al-Basri relied on religion and artistic imagery in his letters. These methods had an effective role in raising the semantic and artistic level. The study consisted of: an introduction, a preface, discussing the art of letters in the Umayyad era and its development according to the new circumstances in society, in addition to explaining the types of letters and what distinguishes each type. It consisted of four topics, the first of which dealt with the life of al-Hasan al-Basri, his knowledge, culture, and his preaching. The second topic dealt with the most important letters of al-Hasan al-Basri that he addressed to the Caliph Omar bin Abdulaziz and the Caliph Abdul-Malik bin Marwan. As for the third topic, it dealt with the discussion of the religious heritage in his letters in all its forms; the fourth topic focused on the artistic imagery in al-Basri’s letters through the use of similes and metaphors. The conclusion includes the most important findings of the study, as well as a list of sources and references that were benefited from.