PURPOSE: A method and a system for a network game are provided to enhance the game capability without the spatial and time limit and to prevent the physical abnormality. CONSTITUTION: The network game system comprises a web server(3) providing a web connection function to the user, a network game server(4) providing the network game to the user, a member information DB(1) storing the user information including a game level of the user and a game DB(2) managing the game time and point of the user. A wire network terminal(5) connects to the web server and the network game server and enables the user to execute the network game. A portable terminal(20) is attached to the terminal and detects the user's real exercise amount that becomes a basis to estimate the physical strength factor. The web server sets up the game level of the user on the basis of the technical and the physical strength factor of the user.
