To provide an electronic commercial transaction management server and a network liquidation system which open up a new efficient retail shop by securing a possibility of affirmative credit discrimination of a credit management device on the basis of the cash transaction history of the retail shop.

An electronic commercial transaction management server 1 is provided with a credit transaction management means 13 which executes credit transaction processing on the basis of a transaction request from a member customer which passes an open network 3. The server 1 is also provided with a credit transaction discrimination means 10 which discriminates whether a credit transaction for the transaction request of the member customer is possible or not, a cash transaction management means 11 which executes cash transaction processing in the case that the credit transaction discrimination means has discriminated that the credit transaction is not allowed, a cash transaction liquidation history management means 12 which stores and processes the cash transaction liquidation history of the member customer by the cash transaction management means, and an evaluation processing means 15 which derives credit worthiness evaluation data for the credit transaction on the basis of the cash transaction liquidation history of the member customer.