An anonymization indicator computation system of the embodiment includes a data storing device, an anonymization device, an anonymization degree computation device, and an addition degree computation device. The data storing device stores original data including a value for each item for each person. The anonymization device generates anonymized data from the original data by anonymizing values of part of items in the original data. The anonymization degree computation device computes the anonymization degree indicating a degree of anonymizing data based on the anonymized data. The addition degree computation device computes the data addition degree indicative of a probability of generating the anonymized data from the original data.