PROBLEM TO BE SOLVED : To provide an auction dividend calculation method for providing a collateral margin as information in the form of a dividend estimation amount.SOLUTION : A certified copy of register for real estate is acquired from a register office; information of the certified copy of register for real estate is inputted from an input device of a computer; and a receivable file with a receivable number attached as a database file, a property file with a property number added, a collateral receivable order file, a receivable priority file, and a property priority file are stored in a file device. Next, the receivable file in the file device of the computer is composed of an original request receival amount, a receivable residue amount, a dividend amount, and a tentative calculation value by attaching an index key to the receivable number by a program as a key item of the database file, and composed by attaching an index key to each of the property file, the collateral receivable order file, the receivable priority file and the property priority file.