The method and system of advertisement using multimedia contents

An advertisement method and a system using multimedia contents for magnifying advertising effect are provided to advertise products shown on a reproduction screen of multimedia contents more effectively, even when multimedia contents files already stored in a client's terminal are reproduced. A client accesses a web page provided from a multimedia contents supply system(A). One of multimedia contents is selected to demand transmission(B). It is searched whether an advertisement image file corresponding to the multimedia content exists(C). Together with the selected multimedia content, the corresponding advertisement image file is transmitted in real time(D). The client reproduces the selected multimedia content and the image file in real time(F).