In this paper we investigated the relation between the surface degradations and anti-pollution characteristics of Room Temperature Vulcanized(RTV) silicone rubber coating that has different roughness through immersing into saline water. We utilized several analytic techniques such as atomic force microscopy(AFM) scaning electron microscopy(SEM) contact angle Salt Deposit Density(SDD) and average leakage current under the condition of salt fog. It is found that the surface roughness of treated RTV silicone rubber increased and the hydrophobicity of sample surface decreased with increasing the duration o immersion into water due to the erosion of base polymer the melting down alumina trihydrate(ATH) and the diffusion of Low Molecular weight(LMW) fluid. Despite the roughness of surface had been increased by water immersion excellant anti-pollution and recovery characteristics were maintained and SDD saturated to 0.1~0.14mg/cm$^2$. The average leakage current under salt fog increased with surface roughness. Measurement of average leakage current will be helpful to investigate surface degradation and lifetime expectation of RTV silicone coating.