البحث هو دراسة للمساجد الجامعة الوسيطة في عدد من المدن اللبنانية الرئيسة ومميزاتها المعمارية والفنية, وأبرز السمات المعمارية فيها وأهمها:
1-     الجامع العمري الکبير في بيروت: وهو من أهم الجوامع الوسيطة في مدينة بيروت وعرف باسم جامع فتوح الإسلام.
2-     الجامع العمري الکبير في صيدا: يرتفع الجامع غربي مدينة صيدا وهو يشبه القلاع بمظهره العام.
3-     الجامع المنصوري الکبير في طرابلس, يقع في وسط المدينة على الضفة اليسرى لنهر قاديشا.
The aim of this research is to describe the main architectural features of major Lebanese mosques and put them within the specified time frame and set a table that identifies similarities and differences among them.
1. The definition of the mosque: There is no verse in the Qur'an or Hadith of the Prophet specifying how to plan mosques, but the habit that was followed in the construction of the first Islamic mosques was the one that was later known in the planning of the mosque. The mosque is an open courtyard in the center surrounded by the halls of the four sides, and the tribal corridor is the most profound corridors and forms the sanctuary of prayer, penetrates the merit of a "mihrab" is an apse that defines the direction of the Holy Qibla in Makah as well as the presence of tribune (MINBAR) near the mihrab.
Major mosques in Lebanon:
1-The Great Mosque of the age in Beirut: It is one of the most important intermediate mosques in the city of Beirut and known as the Mosque of Fatouh al Islam.
2-The Great Mosque of al-Omari in Saida: The mosque rises west of the city of Saida and looks like castles with its general appearance.
3. The Grand Mosque of Mansuri in Tripoli is located in the city center on the left bank of the Kadisha River.
After studying the architects and artificial characteristics of the grand mosques in Lebanon, it will be placed within the timetable and the establishment of a comparative table that determines the similarities and differences among them.