Group buying system and method

A group buying system and a method thereof, wherein a group buying event is created and a purchase quantity threshold and corresponding price of the product are set by a group buying server. When a consumer decides to purchase the quantity of this product through an information device, the group buying server generates a reservation code to record the identity of the purchaser and reserve the purchase qualification of the consumer in advance. Then, the group buying server determines whether the total quantity purchased by each consumer has reached the purchase quantity threshold, and if so, send a notification to each information device based on the reservation code to notify the consumer to purchase the product with a preferential price corresponding to the current total.