The present invention relates to a directional flooding method in a wireless sensor network. Transfer of a packet between respective sensor nodes and a sink node in a wireless sensor network is made with the directivity. To this end, when the packet is transmitted from the sensor nodes to the sink node, only the sensor nodes having a minimum hop count for the sink node are involved in transmission of the packet. Meanwhile, if the packet is sent from the sink node to the sensor nodes within a given destination area, after the packet reaches a corresponding destination area, only sensor nodes located within the destination area transmit the packet. The present invention has an effect that it can improve energy consumed on average and a total number of packets transmitted when transmitting the packets in a wireless sensor network compared to a conventional simple flooding method.