Recently personal information security breaches by unauthorised access, mistakenly disclosure or stolen become more frequent and the scale of the economic loss of such incidents is growing. Assessing economic loss of personal information security breaches is needed for decision making of information security investment This paper presents a framework to analyze economic impact of personal information security breaches and develops formula for each element to empirically calculate the economic loss. We also compared annual economic loss of Korea with that of Japan to develop some implications.