Abstract. Smart Grid has become more important for the efficient use of electric power and the demand reduction. As demand for electric power is increasing continuously despite its limited capacity. The demand reduction in Smart Grid can be achieved through DR (Demand Response) which reduces demand for electric power. In this paper, we analyzed the weaknesses of open source of Open ADR, protocol for Smart Grid DR, using CERT Java secure coding rules. We extracted the violations of rules such as OBJ01-J that means the scope of declaring member variables which should be obeyed in Object-Oriented Programming and IDS00-J that means the validation for input data which should be obeyed in Web environment. By eliminating the weaknesses we could enhance the security of Smart Grid communications.