To provide a stock managing method which can reduce the danger of overstocking at a store and speedily meets the demand of a user.

A system to which this stock managing method is applied is constituted by connecting a buyer's computer 1, a store's computer 2, and an article selling/buying management computer 3 to the Internet 100 and providing the article selling/buying management computer 3 with a customer information database 4. A customer accesses the article selling/buying computer 3 from the buyer's computer 1 through the Internet 100 and registers order information in the customer information database 4 and the store refers to the customer information database 4 from the store's computer 2 through the Internet 100. At this time, the purchase results of the customer are registered as a customer reliability coefficient in the customer information database 4, so the stock can be managed according to order information having a higher customer reliability coefficient and the danger of overstocking at the store is reducible.