Risk management includes phases such as risk identification, risk assessment and risk control. Little work has focused on risk summarization, which is a useful phase of risk management. Risk summarization means a list of occurred risks; risk summarization can also means relative documentation for risk management actions. This study presents summarization indices to evaluate the risk management efficiency. The indices include expected success rate, risk identification ratio, actual key risk ratio, actual key risk identification ratio, etc. The study aims at helping to fill a vacancy of risk summarization in risk management domain.