Method and device for controlling use of external data network via mobile access point

Disclosed are a method and a device for controlling use of an external data network via a mobile access point (AP). A host device set as a mobile AP determines whether a dataless mode is set, prevents a client device from using an external data network via the mobile AP if the dataless mode is set, and permits the client device to use the external data network via the mobile AP if the dataless mode is released. The client device to be connected to a mobile AP determines whether a dataless mode is set in a host device when the client device attempts to be connected to the host device set as the mobile AP while the client device is connected to a wireless data network, maintains the connection to the wireless data network if the dataless mode is set, and releases the connection to the wireless data network if the dataless mode is released.