Commodity price tracking method

The invention discloses a commodity price tracking method. The tracking method comprise transmitting a record of purchasing a commodity to a system by a mobile device, wherein the record of purchasing the commodity comprises the price for purchasing the commodity and the local information of the mobile device; comparing the record of purchasing the commodity with a record of purchasing other commodities of the same kind after the commodity is already purchased; and transmitting the record of purchasing other commodities of the same kind to the mobile device by the system if the price for purchasing the commodity is different from the price for purchasing other commodities of the same kind. In this way, by tracking the price for commodities in a physical store via the mobile device, the invention allows consumers to quickly find out whether the price for the commodities in the physical store is changed.