A system and method for buying goods and billing agency using short message service are disclosed. If a purchaser transmits goods information to a mobile communication service system using short message service of a mobile phone, the mobile communication service system generates a certification code corresponding to the goods information and transmits it to a shopping mall server and the mobile phone. Then, the shopping mall server and the mobile phone exchange messages and run mutual authentication. Thereby, system construction expense for selling goods and service is decreased, purchasing procedure is simple, and the safe purchase can be done by mutual authentication using the certification code.