Abstract: Carbon steel is the most widely used engineering material and accounts for approximately 85% of the annual steel production worldwide. It is also used in many types of engineering application due to the excellent in mechanical properties and a better choice for the cost. However, the usage of carbon steel is limited to its corrosion resistance and tends to corrode easily when exposed to both oxygen and moisture. There is variety of protection that already been implemented to reduce the corrosion rate of the carbon steel including providing a coating with high corrosion resistance alloys. In this study, carbon steel was coated with WC-10%Ni and the corrosion mechanism was observed at different temperatures. The value of corrosion rate was observed from weight loss measurement and electrochemistry test by using potentiostat. The quantitative analysis by electrochemistry analysis using Tafel plot was explained the corrosion attack in terms of open circuit potential, corrosion potential, Ecorr and current density, icorr. The results reveal that temperature and time affect the corrosion rate on carbon steel coated with WC-10%Ni. The most severe attack was identified at the edge of base metal to WC-10%Ni coating interface. This is due to galvanic effect between dissimilar base metal and coating. The value of the Open Circuit Potential (OCP) also increased as the corrosion rate increased. The mechanism of corrosion attack and coating integrity by WC-10%Ni was observed by using an optical microscope and SEM.