Abstract: A routing method for a cluster-based wireless sensor network is provided for improving lifespan of the network and reducing network traffic. A routing method is proposed for a wireless sensor network having a sensor field defined by a plurality of clusters each including a plurality of sensor nodes and a header node, one of the cluster is a head cluster including a sink node. The routing method includes announcing, at least one sensor node which is the sensor node detected an event, the event; requesting, at the sink node, the source node to transmit data required for ubiquitous services; and transmitting, at the at least one source node, data to the sink node. Announcing the event includes relaying, at the at least one source node, a data announcement packet from a source cluster to which the source node belongs to a destination cluster which is arranged along an ith second direction axis through the header nodes of the clusters arranged along a first direction axis of the source cluster.