The use of polymer materials as electrical insulators on transmission and distribution lines has been increas- ing such,as epoxy resin. Several advantages of using epoxy resin as an insulating material are its low density, better dielectric properties, and epoxy resin has higher volume resistivity than that of the glass and porcelain. However, ep- oxy resin has some disadvantages when it is used in tropical areas concerning with the humidity, high ultraviolet radia- tion, acid rain and effects of contaminants. Consequently, insulator surface will be easily damaged due to electrical tracking, which is indicated by the surface tracking. In this paper, the surface tracking on epoxy resin compound with silicon rubber has been investigated. The test was done based on the method of Inclined--Planed Tracking （IPT） IEC 587.. 1984 with NH4 C1 as contaminant. The test materials used were epoxy resins based on Diglycidyl Ether of Bisphenol A （DGEBA） and Methaphenylene Diamine （MPDA） compound with silicon rubber （ SiR ） with the dimensions of 50 mm×120 mm and the thickness of 6 mm. The flow rate of contaminant was 0.3 mL/min. The 3.5 kV AC high voltage 50 Hz was applied to the top electrodes. The experimental results show that the contact angle of hydrophobic was affected by compound of silicon rubber. The surface tracking, time to tracking and discharge current were affected by applied voltage, contamination and contact angle. By using micro--cameras, the surface damage was detected. The severest damaged sample surface on a sample had small contact angle. On the other hand, samples with the greatest contact angle needed longer time to have surface damage in the surface discharge. This shows that it is more difficult for large contact angle samples or more hydrophobic to have surface discharge. Epoxy resin compound with silicon rubber has contact angle of hydrophobic greater than epoxy resin without silicon rubber.