This work proposes efficient data aggregation algorithms for range query in wireless sensor networks. The proposed aggregation and query mechanisms are based on a virtual grid in sensor networks. A sensor node is selected to be a manager, named head, in each grid. The head node detects the generated event, announces event to all heads, and responds the query of mobile users. A user obtains the occurred event information from its grid head. If a user is interested in the event, it issues a query to acquire data of a specified regular-shape or spreading irregular-shape ranges. User can designate a regular range for querying. To track the diffusing event, this work proposes an efficient distributed algorithm for a dynamic tree structure in sensor networks. Users can oversee the spreading event via querying the incurred irregular-shape range. Additionally, this work proposes efficient approaches to gather data from sensor networks when voids exist. Finally, experimental results show that the proposed approaches are more energy-efficiency than the existing approach.