633This paper describes the effects and the aging of silicone compound coatings on ceramic insulators under artificial tropical climate. The improvement of the properties of the ceramics insulators was investigated. The effects of temperature, humidity and various artificial pollutants were also investigated. The experimental results show that application of silicone compound coatings suppressed leakage currents significantly under contaminated environment. The hydrophobicity of the insulators was also improved drastically. Up to 50 oC the coating performed well and the leakage current was remain constant. Under humidity of more than 90 % higher leakage current and lower flash over voltage were observed. The coating on the wet-polluted insulators results in a very poor improvement of the insulator properties. This showed coating method affected the performance of the coating.