The deterioration of reinforced concrete (RC) structure due to chloride attack plays an important role in the reduction of structure strength. Consequently, the actual condition of structure is an essential investigation for management planning in concrete structure which is attacked by chloride. In this paper, the proposed assessment bases on the risk management and the reliability theory presents in risk index (RI) of structure. The reinforced concrete building under the marine environment was an illustrative example for risk evaluation. It was found that the risk index of structure equaled to 20, it implied that the structural condition encountered with extreme risk due to chloride attack and must be rehabilitated urgently. As analysis results, the risk assessment is relation to the actual condition of structure. This assessment can be used as a guideline tool for structural engineering to assess the concrete structure attacked by chloride.