A wireless ad-hoc network for transmitting packets to target regions, and a packet transmission method thereof, are provided. The ad-hoc network includes at least one relay node for receiving a packet containing location information of at least two target regions each including at least one node, separating the received packet by the location information, forming a new packet for each instance of the location information separated from the received packet, and forwarding the new packets to corresponding target regions; and a source node for generating the packet containing the location information and transmitting the packet to the relay node. The present invention can reduce the packet transmission overhead, the packet transmission delay, and the power required for the packet transmission. Therefore, the packets can be delivered to the target regions in an efficient manner.