The synchronizing of cooling loads with solar radiation intensity is an important advantage when we utilize solar energy in cooling or air conditioning in residential buildings. Practical experience confirms that appropriate design of these systems can achieve good results to use solar energy in air conditioning projects if they compared with conventional systems. This paper aims to investigate the theoretical behavior of thermal parameters and their interaction in absorption cooling systems powered with solar energy, which use thermal storage tank and auxiliary heater, with flat plate solar collectors. To achieve this goal, a computational program is prepared to estimate the behavior of different thermal characteristics and coefficients of an absorption cycle, like coefficient of the performance (COP) and solar useful heat gain, in range of generator temperature varies between 80 and 100 degrees C, and an evaporator temperature varies between 5 and 15 degrees C, for a climatic conditions of Aleppo, where the cooling loads data, solar radiation intensity or other information were introduced. We found that there is a good agreement between our computational results with comparison to practical results, or the measurements of installed projects. The results assure too, that it is suitable to install solar assisted absorption cycle of air conditioning system in climatic conditions such as that of Aleppo.