Aluminium alloys are successfully used in marine and offshore structure in purpose of cathodic protection. Aluminium itself has poor electrochemical properties for sacrificial anode applications. Hence it is alloyed with other elements to improve its characteristics. This study was conducted to investigate the influence of calcium addition and also heat treatment on the potential and current capacity of Al-Zn-In anodes. The electrochemical performance of these anodes was evaluated by electrochemical test based on NACE standard method. SEM and EDAX analyses were used to examine the surface structure of the anodic materials. The results were then compared with those of the base alloy without calcium and untreated specimens to understand the behaviour of the anode after alloying and heat treatment.