Before the Islamic Revolution, most of the air force fleet was organized by USA aircrafts. After the victory of the Islamic Revolution, in the late 1980s, the air force was able to empower its air fleet with eastern aircraft. Now, after four and two decades of Western and Eastern combat aircraft operating in IRIAF, it seems necessary to compare the performance of their logistics system; Therefore, the aim of this research is " comparison of western and eastern IRIAF combat aircraft in terms of logistics system". This is applied research, descriptive method and mixed approach. The statistical population is the commanders, deputies, managers and technical staff with work experience in both western and eastern combat aircraft who have more than 20 years of service, which is 210 persons. The method of data analysis in the documentary section is qualitative, and to analyze the data obtained from the questionnaire, statistical analyzes were performed with TOPSIS. According to the results of the research, Western combat aircrafts are of higher quality in terms of ease of maintenance, cannibalize and moving parts between two planes, compliance with maintenance standards. In the comparison of the readiness-material component, in terms of the availability of parts, the adequacy of readiness, western combat aircrafts are of higher quality, and finally the researcher found that the performance of the logistics system of western combat aircrafts is better than eastern aircrafts.