Abstract— this paper presents a systematic study conducted at KFUPM to evaluate the performance of composite insulators, using different types of insulator acquired from many international manufacturers, and field used insulator samples for about 10 years. The study included electrical laboratory testing using artificially polluted samples and field polluted samples. Material study on the properties of composite insulators is investigated considering the effects of the environmental parameters. This has been done with 1000 h experimental tracking, erosion test, and accelerated weathering aging test. To evaluate microstructural changes and measuring the temporary and permanent changes produced by aging, several sophisticated techniques were utilized. Such methods include the Scanning Electron Microscope (SEM) and Energy Dispersive X-ray (EDX) Analysis and Attenuated Total Reflection-Fourier Transform Infra-Red (ATRFTIR) spectroscopy.